Open the package and you will find that it centers around a solid relay base w/ relay.
Grayhill 70-OAC5 Input/Outpt Module, 4-Pin, 2.5-10VDC, 140VAC, 3.5A
The model PSR-SCP-24UC/ESA4/2X1/1X2 2963750 is listed clearly, and you will find that it fits many control panels with ease.