This is the direct replacement sequencing relay for many York, Luxaire, Coleman, Coleman-Evcon, Fraser/Johnson, and Air Pro furnaces made by Unitary Products Group. There are three sets of normally open switching contacts for line voltage and a 24 volt coil to operate the relay. This part is NOT for use on control circuits other than 24 volts. The M1-M2, M3-M4, and M5-M6 contacts close in 1-110 seconds and open in 1-110 seconds. This sequencer replaces part numbers S1-3115-3571, 3115-3571 and 3400-3571.This part is covered by the exclusive OneTrip Parts® two year limited replacement policy. If this part fails within two years from date of purchase, return the defective part and a copy of the original invoice to the place of purchase for replacement. Contact the authorized OneTrip Parts® dealer that you purchased the part from for details.Original equipment manufacturer"s brand name(s) and part numbers are used for identification purposes only. This item is supplied by OneTrip Parts® and meets or exceeds original equipment specifications.