Round lid surrounded by a square frame. Although it is not explicitly stated that this is a sewage cap, according to the shape of the lid and comparison with other similar lids, it seems that this is indeed the designation of the lid.
Translation of the text on the cover: Israel Airports Authority Vulcan Foundries Airport Authority logo Registered sample No. 21405 Moran model Standard mark of the Standards Institute of Israel 1994 20210 V500 8T