Compared to the Chinese ones that are half the price, it seems better. It works with a 5.5kW / 7.5HP 1400rpm motor with 420/400 pulleys, the second one on the motor, so about 1330rpm. At 8.5bar the motor is already running above its nominal, so the 11bar they claim it will NOT reach with 5.5kW unless you lower the rpm. The noise is considerable. I recommend fewer rpm to reduce noise, reduce load, and improve performance. Since its use is for backup, I am not changing pulleys and belts. If I used a 4kW motor, I would use a 280mm max pulley for 8 bar.