Sheridan intermounts bolt onto the barrel and make a little scope rail for red dots or scopes,hard to get hold of nowadays......steve D had some for sale recently on here at bargain price,they went pretty quick.
link to
mounts.......http://www.crosman.com/airguns/acces...ics/rings/B272
and here's mine bolted on.http://i158.photobucket.com/albums/t...4/P1090190.jpg
if I see any knocking around I'll give you a shout (pm)
Keith