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

Excellent add on to alarm system

It works just follow the instructions

on door and frame fine when the cover doesnt keep flipping open - which it does a lot- even with the screw inserted properly. lets the Yale system down im afraid- better with a PIR

Makes setting and unsetting very easy.

Easy to add onto current system does the job

Just the job and quickly sent.

likeit

Excellent product

handy extra sensor for other doors/windows

Cheapest from everywhere.Very good deal.