Number of Grooves 4. Clutch Diameter 134 mm. Compressors are the heart of the A/C system, with a heavy responsibility to pump A/C refrigerant throughout the automobile's A/C system. That's why UAC take the upmost care when developing new compressors. UAC branded compressors meet exact OE specifications, and that they are manufactured at a tier 1 facility. When you purchase a new compressor from UAC, you are receiving a high quality product at price that is very affordable.