Rotary screw air compressors. To be precise, they are portable air compressors, which are usually rotary screw air compressors. Because of it structural characteristics, it can not only be relatively compact but also able to provide enough compressed air and pressure to supply most pneumatic tools, such as nail gun, air ratchet wrench, air hammer, impact wrench, air stapler, air sander, spray gun, sandblaster. Powerful enough for home use and DIY’er.