I'm no professional, so take my comments with a pinch of salt.

I replaced the lock on my own. This cylinder comes with 2 round notches (i assume is a security feature), that did not fit into my current door locking system. In the end, i had to carefully file down the notches for a nice snug fit. Its done the job. It feels a lot more sturdy and good quality compared to my generic cylinder.

Recommended by a professional locksmith as the one fitted by the builder 10 years ago was poor quality and not very secure. This is a 70mm one, there are other sizes.

I know have peace of mind knowing that my locks cannot be snapped and bumped.

They also fit much better than the old ones which I replaced.

Fitting them was so easy. Each lock only took about 5 minutes to fit.

www.safe.co.uk were so much cheaper than buying the locks from te manufacturer or the large suppliers.

I have also fitted the same locks for my in-laws and gained some 'brownie points'!