I don't know the exact part numbers but supco makes these little hard start kits 1/4-1/3 hp and 1/2hp. power your 110 vac through the 2 blacks and common is black start is white and run is red. for small reach in compressors. ive used them for years works good but recently the last 2 that I used was the 1/4-1/3 hp for a 1/3 hp compressor. compressor is amping within compressors name plate rla. but overload in hard start kit still overloads after running for about 5 mins monitor amps they don't spike up or nothing odd like that, no my voltage doesn't drop out of no where. I feel since its a 1/4 - 1/3 and its a 1/3rd hp comp. its on the high end and the overload is not strong enough. ive bypassed overload in the kit to make sure compressor runs good and it does. I think these things should have an amp rating along with hp rating. im going to find a supco tech support number and call ato find out whats the rla max for these start kits but im wondering if others run into this issue or do they know the answer to my question??????????????