AKSESS 400 - The trademark name of a cover type in the manufacturer PAm
The manhole cover is similar to other caps of the same type, but the current cap is general and is not intended for a specific consumer and the purpose of the cap is not specified. See another cap for example Click for cover's details
GS - Spheroidal graphite cast iron - a special cast iron in which the crystallization of carbon has been slowed down, which makes it close to steel - also called ductile iron (Thanks to Vuori Susi for the clarification)