List below is a quick overview to the differences between the 5-2-1 Compressor Saver® and other types of "hard start" or "soft start" devices.

Features	5-2-1 Compressor Saver®	PTCR Devices	Timing Devices
Uses Potential Relay	Yes	No	No
Reads Back-EMF (senses when compressor is running)	Yes	No	No
UL Recognized	Yes	No	No
Approved by Compressor Manufacturers	Yes	No	No
Approved by Equipment Manufacturers	Yes	No	No
Used by OEM Manufacturers	Yes	No	No
Affected by Ambient Temperature	No	Yes	Yes