"Easy to fit door closer, use 22 mm drill and be careful to keep hole level and straight. You will need to chop out the recesses for the screw plates. You can use the radius plate to hold the spring extended whilst you screw the 2nd plate to jamb. The supplied screws are weak, I broke one screwing it into a hard wood door even though I used a pilot hole. No matter, I prefer to use Screwfix turbo gold screws anyway."