3 1/2" Domed Concrete Survey Marker (Aluminum)
Berntsen "C" style aluminum concrete markers (US Army Corps of Engineers Type 1 Disc) has the classic 3" (76mm) long split-style tapered stem with inverted "Y" design for anchoring into concrete and rock. It is available in 3½" (81mm) diameter and one-piece orbital formed from solid 6000 series aluminum.
The CAPMAG ceramic magnet can be used with these concrete markers to assure easy detection of the mark with a magnetic locator up to four feet deep.
C35D Concrete Marker Installation Instructions