From what I can tell as a non-EPS owner, the EPS is a 509T but cut for RMRcc (507k) footprint, allowing it to sit lower and work better with direct milled guns. . Sent from my iPhone using Tapatalk. Web. 28. Holosun EPS & EPS Carry - Enclosed 407K/507K Holosun is releasing enclosed micro dots that fit the 507k footprint.