that means if you have one circuit feeding two separately switched banks of lights you shouldn't use that style dimmer. like if you have your kitchen lights on the same circuit as your living room lights, and you tried to dim both sets of lights, it may mess with the dimmers somehow. not really sure anout the ELV dimmer. i have heard of a magnetic low voltage dimmer, but not sure on either of them. i am going to use the leviton vizia+ dimmers on these. I am going to hook them up this week to the living room lights. i see no need to dim the kitchen lights, so no dimmers there. hope you figure it all out, these are some nice lights. I have gotten quite a few people asking about them already when they see them.