I used a SEB pressure cooker for 5 years, which was confiscated by a relative, so I decided to get a new one.
The WOLL pressure cooker is an amazing tool for every professional or amateur cook.
It has a unique way of closing and opening with a click-clack, while all other pressure cookers are difficult to close and open, and the lid's sealing flange is made of silicone and not just rubber. It has a safety valve (white in case the kitchen is very hot) and the unique Safe Window in case you forget the cooker on the stove and leave!!
The pressure of the WOLL pressure cooker is 0.6Bar on the low scale, while on the high scale it is 1Bar and Max=1.8Bar.
The SEB and Tefal Clipso on the low scale are 0.85Bar, while on the high scale they are 0.9Bar and Max=1.6Bar.
The Fissler Vitaquick on the low scale is 0.45Bar, while on the high scale it is 0.75Bar.
The Fissler Vitavit Premium on the low scale is 0.45Bar, on the medium scale it is 0.6Bar, and on the high scale it is 0.75Bar.
I highly recommend the WOLL pressure cooker, it is the best choice on the European market.
25 years warranty for the body of the cooker and 3 years for the valves and handles.
I have cooked giant beans in 20 minutes and they turned into a paste, while in a conventional cooker I boiled them for 2.5 hours. I have cooked green beans with peas in the steam basket in 10 minutes. Fish liver in the steam basket in 30 minutes and it became very tender without being soaked like when boiled in water, so the meat in steam is enjoyable for the elderly.
This cooker is 6Lit but like all others, it is filled up to 2/3 of its volume, approximately 4Lit. The dimensions are base diameter = 18.5cm, top diameter = 24cm, height = 18cm, and with the lid height = 20cm.
I use the 15cm eye with 3 settings and the 18cm eye with 9 settings.
It is ideal for a family of 2-4 people. I have only cooked on the high-pressure high scale of 1bar.
You can cook giant beans for 6 servings in 30 minutes on the high scale, rolled meat for 4 servings in 40 minutes, green beans/peas/corn in the steam basket for 4 servings in 10 minutes, a medium-sized chicken cut into pieces in the steam basket for 4 servings in 30 minutes, if you put the chicken without the steam basket and fill water up to the 1/2 mark, you can make chicken soup for 6 people in 30 minutes. Turkeys are usually larger than the cooker, but you can put half a turkey in pieces in the steam basket, but you will leave it for 40 minutes. If you put broccoli, cauliflower in the steam basket, you should only leave them for 5 minutes on the low scale because in 10 minutes they will become mushy, at 5 minutes turn off the heat and leave them for another 5 minutes, then follow the Opening Procedure.
More information here:
https://woll.de/shop/unsere-serien/edelstahl-kochgeschirr/pressure-pro/
https://woll.de/media/pdf/52/91/8e/Pressure-Pro-Use-and-Care-2018_IB_148x148-DE-EN-SCREEN.pdf

GENERAL INSTRUCTIONS FOR USING PRESSURE COOKERS
You need to experiment with your own cooker in your own kitchen and measure the times. If you change the cooker or the kitchen, then you need to repeat all the experiments from the beginning.

CLOSING PROCEDURE
1) I added warm water from the kettle slightly above the MINIMUM mark so that I don't have to wait too long for it to boil. After the 30-minute cooking time, during which the pressure cooker constantly released steam, the water had only reduced by 10%-15%, while I was worried that the water would run out and expected it to have reduced by >50%.
2) I add the food with spices.
3) I press the 2 red buttons on the handle on top of the lid and hold them down, adjust the lid by aligning it with the pot, press it lightly and release the red buttons, then the lid closes with a click and the black arrows on the top of the lid should be hidden in the perimeter, if they are visible it means that you haven't aligned it properly and it is open.
4) I adjust the pressure selector, which is on the regular valve, to position 1: (low pressure position 0.6Bar) or position 2: (high pressure position 1Bar), there is also an intermediate click without indication. See in the photos.
I don't leave but wait until steam comes out of the regular valve and then lower the intensity to the minimum.

COOKING PROCEDURE
1) I check the pressure selector on the regular valve (low pressure position 0.6Bar) or position 2: (high pressure position 1Bar), if it is in the desired position according to the type of food.
I place the pressure cooker on No7 on a burner with 9 levels of diameter 18cm or on No2.5 on a burner with 3 levels of diameter 15cm. Do not use a burner >18cm, which is the diameter of the bottom of the pressure cooker.
After about 2 minutes, the red valve rises and starts releasing steam, but after 1 minute it stops. As long as the red valve is raised, it means that the pressure cooker is under pressure and do not attempt to open it by pressing the 2 red buttons, which will probably be impossible to press due to the pressure on the lid.
2) After about 1 minute, the regular valve starts releasing steam. From this moment, cooking time starts counting and not from the beginning. Then you must immediately lower the intensity to the minimum on No3 on a burner with 9 levels or on No1.5 on a burner with 3 levels because I know that on No1.5 the water boils while on No1 it is just warm.
3) Throughout the cooking time, the regular valve should release steam at a low speed.
If the regular valve releases steam at a high speed, it means that you need to lower the intensity a little on the burner. If the regular valve stops releasing steam, it means that you need to increase the intensity a little on the burner. Now you can leave for 10-30 minutes and come back to turn off the burner.
4) If you forget to lower the intensity on the burner in step (2), then the white safety valve will open, which means that the pressure is 1.8Bar, then you need to lower the intensity on the burner and in 1-2 minutes press the white valve down with a spoon or fork because otherwise it will keep releasing steam and the pressure won't increase.
If you completely forget and are on the phone or on Facebook, then the Safe Window will open, which is on the side of the lid and it means that the pressure is dangerously >2Bar. Then you need to move the pressure cooker away from the burner, turn off the burner and wait for 30 minutes until it stops releasing steam and follow the Opening Procedure. It is advisable not to use a pressure cooker or conventional pots again, but to engage in milder hobbies.
When the Safe Window opens and you are away, in 10-15 minutes the water inside the pressure cooker will run out and it will stop releasing steam and the bottom will warp, or it will turn red and the handles will melt and eventually the pressure cooker will be destroyed!!.
5) When the desired cooking time is reached, turn off the heat and leave the pressure cooker for 5 minutes before starting the Opening Process.

OPENING PROCESS
1) Turn off the heat and wait for 5 minutes for the pressure to decrease.
2) When steam stops releasing, turn the selector of the regular valve to the low pressure scale of 0.6Bar and wait until steam stops releasing again.
3) Turn the selector of the regular valve to the steam release position and wait until steam stops releasing. Then the red valve should descend.
4) To make sure there is no pressure in the cooker, press the lid downwards and see if it is elastic. Then press and hold the 2 red buttons on the handle on top of the lid and lift the lid. Be careful not to get burned as the cooker and the lid may be hot. If the lid falls down, the valves or the handle may break.
The photos can be found here:
https://postimg.cc/gallery/qCBbX9v

DRAWBACKS
I searched a lot to find drawbacks that I do not consider significant, that's why I gave it 5 stars.
1) The indications on the pressure selector on the regular valve are not visible and can only be seen with strong lighting. Instead of using 0: (steam release position), 1: (low pressure position), 2: (high pressure position), they used some indistinct designs that are pointless.
2) The instruction manual has gray letters on a gray background, which is a big inconvenience.
The fact that the instruction manual only includes German and English and not Greek is insignificant, as most translations in Greek are incomprehensible and we need to refer to the English text to understand what it means.
Good luck.