This cap is used as part of the Newcon system. The Pipe Guide ( link) would be installed on the Newcon steel plate ( https://mrmanhole.com/product/newcon-plate-with-ring-t-stops/) and a short piece of 4' plastic pipe set vertically with this cap placed on the pipe. An I.D locator ( https://mrmanhole.com/product/newcon-i-d-locator/) would typically be placed on the cap.

Part#: P-MM0535

Product Link: https://mrmanhole.com/product/i-d-locator-cap/

Resource: https://mrmanhole.com/pavers/