I have a spare pair of these for sale. Originally had them on a 22 Kalibrgun Cricket. Cost around 60 quid from Swillington.
Immaculate condition. Do a good job of securing the scope from my experience. Fairly sure they are mediums (but will need to check that).
They are not quick release.
Can provide pictures and dispatch on Friday (along with Foxyloxy's clone Atlas)
PM me with an offer