This is a purpose built mount for the Hogster thermal sight. We optimized the system for usable eye relief, proper height, and compatibility with a BUIS. We did actual testing in real hunting situations, and the setup allows for very comfortable positions from the prone to standing. Thermal sights typically have very limited eye relief , so it is of the utmost importance that the system is tested as a whole. We designed the riser to also have front/back adjustability, and give you three options for locating the riser to the base unit.
The fasteners that secure the Hogster sight itself to the adjustable riser are METRIC fasteners. You must use a 3mm Allen wrench. The factory supplied mount is secured with both fasteners and an adhesive. Once the fasteners are removed LIGHTLY tap the mount (factory original) until it pops off. The Hogster utilizes pressed in threaded inserts within the plastic/polymer sight body. Do not over tighten the fasteners when installing the sight to the Bobro Engineering riser. You can use low strength thread locker if desired, but use very sparingly if you go this route.