The range tester is used to test the performance of the SureFlap microchip cat flap. The square end represents a cat’s head and activates the antenna, while embedded in the sliding part of the range tester is an identification microchip similar to the one in your cat. First of all you need to program the microchip in the range tester into SureFlap. Remove the battery lid and press the memory button once to put SureFlap into the learn mode. Now slide the microchip to the top of the range tester as we are showing here. Put the square part of the range tester into the middle of the tunnel until it touches the door. The light will stop flashing once the microchip has been stored to memory.Now remove the range tester from the tunnel and the motorized catch will close. If the microchip cannot be learnt, please remove SureFlap from its installed location and repeat the learn process. With the microchip stored in memory the range tester is ready for use. Slide the microchip to the small end of the range tester as we are showing here. In one movement move the range tester into the middle of the tunnel until the front of it touches the plastic door. If the chip is read then the motorised catch will drop down. If the catch does not move remove the range tester from the tunnel and slide the microchip 1cm up the range tester. Now put the range tester back into the middle of the tunnel until it touches the plastic door. When the chip is close enough to be read the motorized catch will drop down. We need to know the furthest distance on the scale on the range tester at which the door opens reliably. The door should unlock with the chip around 25cms.If the reading on the range tester is 20cms or lower then the range is being reduced. The most common cause is metal in the skins of the door or around the hole. To confirm if this is the problem please remove SureFlap from its installed location and repeat the tests. If the range is less than 25cms once SureFlap has been uninstalled this may be down to electrical interference, and the best way to test for this is to test the unit outside or in another room of the house. After completing the tests please contact SureFlap customer service with the results, specifically noting: Your cat’s microchip numbers The distance at which the chip opens the door .