Rotary vane compressors each have four self-wearing carbon vanes, when the vanes become worn to a certain point you will notice a large reduction in air flow. These repair kits include four new vanes, a new gasket and two new black, internal air filters. This listing is for a brand NEW Gast K478 EasyPro RV33V Stratus RVee service/repair/rebuild kit used on 0323/0523 RV33 oil-less "Q" models with internal filtration. Service kit returns your unit to original factory performance specifications. Recommend for service every 2 years. Important: Use Gast AH225D flushing solvent to flush debris from pump when servicing unit (not included) Service kit includes: (4) AH850A Vanes, (2) AK524 Filters, (2) AK473 rings, (1) AK521 Gasket and Instructions. ​ Fits many 0323 and 0523 units including 0323-101Q-SG588DX, 0523-101Q-SG588DX, 0523-V184T-SG588DX and 0523-V191Q-G588DX models.