What stands out about the plug and play approach is how quickly you can move from box to operation.
50pcs SRS-05VDC-SL SRS-12VDC-SL SRS-24VDC-SL SRS-05VDC-SH 6pin 4100 3A Relay
this relay is the Honeywell brand, a nice touch when you want something known.
A nice touch is the even finish on the casing, and Jsdan keeps it consistent across different production batches.
the brand is Crydom, a nice touch that helps when you are comparing parts.