Microchip pet door (Wood Street E17)

Pet door that was in use for 2 years. Removed a year ago as doors to garden were changed. It was working very well at the time it was removed. The white plastic frame is sun-worn but otherwise in good condition. One RFID tag that came with it. Instruction booklet also available but all but the English language instructions cut out of it. Will need 4 x C batteries to operate it. Please see listing on Amazon for more details re size and how it works:
Sure Petcare SureFlap Microchip Pet Door for Cats & Small Dogs with Curfew Timer, Compatible with RFID Collar Tags and Microchips, 1-Button Control, White, 4 x C Cell Batteries Required, Not Included
https://www.amazon.co.uk/dp/B009NH6NR0?ref=cm_sw_r_cso_wa_apan_dp_2AZH0NTRR...