We needed a lockable catflap because we had started to be pestered by neighbourhood cats coming in and leaving their trademark in the house. Although our cat wasn't chipped, having read the reviews, we decided on a chip-readable model from Catflaps. (We had previous experience of collar-worn magnetic ones and decided against going that way). First job was a trip to the vet to get the chip implanted. Next, installation of the catflap - which was straightforward thanks to clear instructions. The training mode is ideal to get the cat used to the new catflap and then it was crunch time. The catflap electronics performed perfectly first time in recognising the chip and thereafter on his first solo run, the cat made a triumphant entry. Job done! Highly recommended.