The 5-2-1 compressor saver protects vital air conditioner components by significantly reducing the amount of time it takes for your compressor to start, in some cases up to 50%. This means that your air conditioner and compressor will bear half the stress, strain, and heat each and every time it starts. This compressor might save thousands of dollars by not having to replace the air conditioner.3 wire hard start kit is pre-wired potential relay and start capacitorReduces time compressor is on high amp start up, which helps prevent the dimming effect of household lightingThree color coded wires to connect for ease of installation Instant re-startFor use on reciprocating and scroll compressors