Cat flaps come in a variety of shapes and styles, although mainly in just two colours, white or brown, although there are a few exceptions. They have a variety of features depending upon the type and cost. The basic feature that most cat flaps share is some form of manual locking. This may be a slide-in closing panel, two way locking (free access or locked), or four way locking (free access, in-only, out-only, locked). The manual locking is generally operated via sliding or rotating catches.
There are four basic types of cat flap. These are manual, magnetic, infra-red and microchip, with the type referring to the operation of the lock. I do not recommend the use of the magnetic or infra-red types due to the required bulky collars, which can be lost. I will concentrate on the manual and microchip types as I have never encountered the other two types in practice
Manual Cat Flaps
If you are looking for a cheaper option then look at manual cat flaps, but please be aware of their limitations
Pros: cheap, no batteries to replace, simple manual controls
Cons: any other cat or small animal may use it. The lock has to be manually operated as required
For further details see the Manual Cat Flaps page
Microchip Cat Flaps
I only recommend and use products from the Sureflap range, so the following refers to those. The microchip models start at around four times that for a typical manual cat flap and upwards depending on the features provided. The microchip control automates the operation of the lock, with either additional selective manual or electronic locking. The cheapest model controls which pets can gain entry, the next level allows differentiation between your pets if you wish to restrict individual access and egress, and the higher end provides timers and phone app control to do all of this automatically
Pros: controls entry by reading your cat’s unique microchip implant (up to 32 pets at any one time). Models are available with a ‘curfew mode’, which locks and unlocks the flap at specified times of the day. Some models can restrict some pets to indoors-only, while others are allowed outside and back in again. The latest models are phone app controlled
Cons: Metal skins or foils in doors affects the microchip reader, requiring specialised fitting. Some cat owners may be uncomfortable with microchipping, although collars can be used
For further details see the Microchip Cat Flaps page