The ADM Universal Adapter Block converts metric hole spacing to standard hole spacing. So for example, it enables you to fit tube-rings with metric spacing to a traditional dovetail with imperial spacing (by 'spacing' we mean the centre-to-centre distance between screw holes).
The adapter is 4" long, 1.25" wide and 0.5" thick. It has drilled and tapped holes, centred, 1"on centre, 1.5" on centre, 2" on centre and 3.5" on centre.
Countersunk holes accept 1/4x20 socket head cap screws (eight stainless steel screws, four for each UAB, are supplied).
Manufactured from premium quality black-anodized 6061 aluminium and stainless steel.
Price is for a pair of adapters as shown in photo.