Herpstat 1 By Spyder Robotics Proportional Reptile Themrostat 700 Watt Top of the Line Proportional heating constantly monitors and adjusts amount of heat necessary to maintain a target temperature (Usable range from 50F to 140F or 10C to 60C). Can also be used in non-proportional (on / off) mode Night Drop capability when used with optional cable Precision Sensor with internal resolution of .1125 F and is accurate to  .9 F Allows display and setting in tenths of a degree Sensor Matching allows the user to digitally calibrate the sensor output to match other equipment