Abstract: A fitting (26) for rotatably supporting a conduit (22) in a bulb-shaped slot in a wall (20). The fitting (26) has a pair of spaced parallel fiats (38, 40) defining a minor dimension for sliding into the narrow entrance (14) to the circular seat (16) of the slot and a larger circular major dimension (36) for rotating into a locked position crossways the entrance (14) to prevent removal of the fitting (26) from the slot. A radial web acts as a stop (50) to prevent backward insertion of the fitting into the slot and for engaging the edge of the entrance (14) in the locked position to prevent the retention arm (46) from overriding the retainer recess (18).