This SU consists of red tufo slabs partly visible underneath SUs 6178 and 6161. The depth of the slabs in the room is notable because they seem as if they may go below what we believe to be the earliest floor level (SU 6161). We hypothesize that the slabs may be part of the lining for one of the numerous drains in room G-1. The slabs are in relatively good position to line the western part of a drainage channel possibly connected to an early cappuccina drain (SU 6216).