Daystate Air Ranger Adjustable Hamster. 1/4" UNC bolt.

The hamster does not require any holes or modifications to
the stock and utilises the stock retaining bolt position.
A longer stock retaining bolt is supplied with the kit.
The hamster fits stocks with a 1/4" UNC retaining bolt and
with a 20mm diameter counterbore in the underside of the stock.
The collar and mounting post are made from black anodised aluminium.
The palm shelf is machined from delrin.
The photo below shows the existing stock retaining bolt and top hat insert washer. The top insert is re-placed inside the hamster mounting post.