Insert with 9 mm rail for front sight for GAMO CFX air rifle

Standard 9 mm "dovetail" rail mounted instead of the front of the front sight in the Gamo CFX airgun muzzle device.
The rail allows to mount a custom front sight, e.g. a tunnel front sight, in the place of a factory front sight.
The 9mm rail, when fitted to the Gamo CFX muzzle device, is positioned 1.5mm below the RRR rail that is factory mounted on the standard 11mm air rifle rail.
The insert has a 9 mm wide rail as standard, but it is possible to order an insert with 11 mm and 13 mm rail, and even with threaded holes.
Then please provide relevant information in the form.

Weight: 4.3 grams
Length: 31 mm
Overall width: 14.7
Mounting to: Gamo CFX muzzle device
Additional top rail: 9mm dovetail rail
Height relative to the 11 mm main rail: -1.5 mm
Material: PLA