Yale EF-DC Easy Fit Alarm Door/Window Contact, White, DIY Friendly, Accessory for SR & EF Alarms, Suitable for Main Access Points

They are just not designed to fit a bit not squared doors. If your door has an indentation or if you are using it with french doors it would just not work well and you would have to tinker with it

very easy to fit ay a good price

Great item and service

This thing makes my alarm go off when the door is opened. That was why I bought it.

Good value for money

Works sound, easy to use and it was easy to connect to the hub so no drama, only issue after 2 days battery run out, but flew the pound shop and brought some batterys, had it changed in minutes,since then sweet as a nut,

Product as described.

handy extra sensor for other doors/windows

Easy to install

Easy to install and connect