Here's a link to that listing for the Diana:-

https://nmproducts.ltd.uk/air-rifles...diana-silencer

P.S.....I'm not linked to them in any way but a satisfied owner. And I think they're in .22 flavour only. Mine prefers JSB Jumbo RS pellets.

P.P.S.....Be prepared to, maybe, have to glue the cheekpiece to the adjuster posts.