Gehmann #839 Series Quick Adjustable High sight base / Riser block set

839 Gehmann Multi-height sight base set with quick adjustment"

Individually adjustable aluminium multi-height sight base set 
Vertical adjustment from 26.5mm to a maximum of 47.5mm in 1mm increments, starting with 6mm of quick adjustment
Supplied with:

4 x sets of packing discs (4 x 1mm, 4 x 2mm, 4 x 4mm, 4 x 8mm)
4 x sets of matching length screws

Additional lateral shift of 5 or 10mm 
Height quick adjustment without the need of tools 
Vertical and horizontal scale to control the settings 
Stable steel clamps with spring return mechanism for a firm fit
Compact design 

839F   Feinwerkbau 
839A  Anschütz 
839W Walther