Q: What’s the difference between ITC-100V/ITC-106V and ITC-100R/ITC-106R?

A: 1. Pinch the two tabs and slide the cover off the entire unit.

2.Side-by-side you’ll notice that the one on the left has an extra relay (circled). This is the ITC-100RL

3.If you see two blue resistors like below, then you have the ITC-100VL which can be used with Solid State Relays (SSR).