compact red laser sight is only 58mm long, with black alloy casing which is shock and water proof. Complete with integrated Weaver / Picatinny mount, and if you switch mount around it will fit Dovetail rail. Package includes: Red laser sight <5mw 3x Batteries AG13 / LR44 (not warrantied). Picatinny / Dovetail dual mount. allen keys. windage & elevation adjustment. Push button on / off. I have a barrel mount and scope accessory mount listed separately that will fit this as in the photo. I have 222 Loctite listed and its recommended to use on the screws.