UPVC Screws. It is quite easy to mix this up with the more common Mila UPVC Door Lock Case Gear Box (our part reference 558). Mila 4500 Extendable Upvc Door Lock Fitting Tip Mila 4500 35 ZP Multipoint 4 Roller Cam Extendable 35mm Backset Lock Case Gear Box.
eBay