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

Excellent. Battery life short.

It was broken

Easy to instal, and pair with my existing system.

Easy to fit, but I had to replace the same one with this one after just over 2 years use, so not impressed with its reliability, hence only 3 stars.

Cheap and cheerful

To replace another door contact.

Very pleased with item and delivery. They are add on for my Yale alarm

It does not work my tale system

Perfect

Just the job and quickly sent.