AstroStreet Optical Dot Sight with Hot Shoe Adapter For Camera Red & Green Reflex Sight with 4 Reticles Easy to attache at hot shoe on a camera without any handwork. Just slide the mount into hot shoe and turn a dial of the adapter. Product for astronomy ,wild bird photography, it is high specifications, higher-grade specifications more. Hot shoe size : 18.5mm *18.5mm *2mm (standard size) Body size: 64mm in height X 90mm in length X 38mm in width Weight: approximately 140g 5 brightness settings, 4 different reticle designs, Red & Green illuminated(Row & pattern are might be different from the photo)