This block, along with SU 5444, seems to constitute a threshold to Space 10. Each block is abutted by small concrete walls and then piers suggesting that the blocks are the only features which present an accessible access point to Space 10. The lip may represent a door-stop like feature. However the lip could present a slight walking hazard and beyond the pier on the west side there does appear to be a threshold into Room 14 as suggested by a cut channel in a tufo block which could have contained a sliding door. SU 5445 instead represents a more monumental threshold to the paved ramp (SU 5462, 5446, 5321).