This is a purpose built mount for the Hogster line of thermal sights.  We optimized the system for usable eye relief and proper height. 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.