An overhead halogen light source is in a constant on state. A pre-focused heat source supplies an area of 4X6mm stimulation to the tail. A built-in sensor in the tail groove detects the tail flick of the animal. The tail groove is a non-metallic material to avoid unnecessary conditioning of your animals; unlike other systems. If the animal does not flick their tail within the pre-programmed cut-off time; the heat source shuts off automatically; avoiding tissue damage. Built-in timer displays the reaction time in 0.01 second increments. Control of system can be from either the front panel or supplied Foot Switch to Start, Stop or Reset tests.