*** SPECIAL ORDER - MINIMUM 4 WEEKS DELIVERY ***These Microclimate thermostats are Pulse proportional thermostat controlling up to 600 watts of any non light-emitting heat source. These units are fully wired with a flexible probe that can be positioned inside the vivarium with the unit sitting on the outside. This allows you to drill a small hole in the vivarium to pass the probe through leaving the control unit on the outside. The thermostats are extremely accurate and great for use in vivarium..