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

easy to install. work well

Fast service, installed next day

Easy to install

Good product fast delivery

Easy to install

Very easy to install and fit against the door to allow the alarm to work. The batteries are very easy to change with small screws to come undone allowing the top to come off without it being removed from the door. I find it very handy that it allows you to press a button to check whether the battery is still working and not dead.

Does the job

Easy to install

It was broken

Very good