ok im running 2 Hydrofarm MTPRTC Digital Thermostat For Heat Mats the reason im running 2 is the first 1 i bought didnt stay programed so they sent me another to replace that one and a couple days later i recieved another one. they work fine its the turn on heat up to the set temp then turn off and drop back down below the temp i set it for then turn back on. i wasnt sure if they all were like that or if they would stay at the programmed temp at all times thank you.