Yale YC2100 Double-Entry Lock Cylinder, YC2100 DB 40X50 NI

This seems a high quality lock with the emergency function that allows it to be opened with a key from outside, with a key inserted inside. Other similar barrels from other makers are available but only at multiples of the price paid. Key is inserted horizontally and is a little more fiddly than a traditional Yale, but this seems common to the competition. 5 keys supplied a bonus. Fitted easily. Limited barrel lengths available however.

After buying my locks this is the only one that was working perfectly with smart locks. Specially the Aqara U200. Highly recommended.

great product and can always rely on decent quality with Yale... comes with five keys which is very useful... double entry lock perfect, easy to install

Keys are a bit figity to get in to the lock but love the lock due to having being able to open the door from the outside whilst a key is in the lock on the inside

Simple task to replace faulty lock cylinder.

Fits well, easy install

Yale door lock replacement with 5 keys.Arrived in good time in packaging I would expect from Yale.I have bought some other "Yale" items from Amazon, that raise the above point.The change from the old lock to this new one took 15 minutes, it was my first time doing this job.The insertion of the keys from both sides was a little tight to start with, but it soon loosened up with use.Would I buy another = Yes.

Using this with the yale linus lock as I needed a lock that would unlock from the other side while a key is in it, was a quick installation with no hassle. I also bought this for the anti-snap protection over the adjustable cylinder lock that Yale recommends as my door for a 35/35 has the cylinder exposed on the outside.