I've just bought a replacement front sight assembly from eGun for my FWB150. It came fitted with a post element and a magnifying lens. The lens is held in a brass mount, inserted into the sight assembly from the front. The glass does not appear to be of particularly good quality, no coatings and some image distortion everywhere but the centre. I would guess magnification is about 1.5x. I understand that these are not permitted under ISSF rules, but as I only shoot beer cans that's not an issue Has anyone used such a lens before? I've no particular questions, but it's a quirky bit of airgun paraphernalia I've not encountered before. I'm looking forward to trying it out as soon as the weather improves.

Matt