https://www.jpcorry.com/jp-corry-products/st-gobain-pam-inter-ax-d-i-manhole-cover/
Saint-Gobain PAM UK Inter-Ax D.I. Manhole Cover
Description
Saint-Gobain PAM UK Inter-Ax DI Double Triangular D400 Access Cover.
INTERAX2 D400-N DOUBLE TRIANGULAR COVER AND FRAME KITE MARKED
RECOMMENDED FOR USE IN: Carriageways carrying continuous heavy traffic
Datasheet :- Inter-Ax-2