This is a custom made picatinny rail for CP99.

Dimenions: 22 mm (actual dimension 21.3mm) rail  for attaching red dot sights, overall length 50 mm.

Material: plastic reinforced with carbon fiber.

Fixed by 2 longer screws (included), a bit fiddly to fit for first time, may need some adjustments. 

Adjustable for windage as the original sight plus it has two glow in the dark dots, so it can be used as normal sight if there is no optical one. 

This rail is a replacement of the rear sight, which has to be removed.

Will suit only the Umarex made CP99 CO2 powered airguns. 

Note to eBay:
This item is NOT a firearm part or accessory - Please don't end this listing in error.