Hi - I checked the specs for my HS503R which came with ". . .and a low mount (.75”) for low-comb height rifle applications." quoted from H-website. The 'main body' looks the same as yours (again on the website) so the low-mount piece should be available (my italics). I'd contact Holosun OR post a WTB on the EE. someone may have one that does not use it. Sorry, but I'm using mine.