Also forgot to add, from what i am aware of, the only VE that is a dimming proportional model is the VE200D. All the others are pulse proportional. Really doesnt make that much of a difference but something to note. All the Herpstats from Herpstat 1 and up are both pulse and dimming proportional. I personally prefer dimming as it just throttles the power where as pulse proportional cycles on and off really fast. Supposed to relieve the hum of heat tapes on metal grates.