Berntsen 4" Bronze Flat Concrete Marker
"C" style (US Army Corps of Engineers Type 1 Disc) has the classic 2 3/4" (50.8mm) long split-style tapered stem. It is available in 3-1/2" (89mm) or 4" (102mm) diameters. Orbital formed from solid unleaded silicon bronze bar.
The CAPMAG ceramic magnet can be used with these concrete markers to assure easy detection of the mark with a magnetic locator up to 6 to 12 inches deep,
depending on soil conditions.
The C4DRL countersink drill bit is made specifically to perfectly recess this C4FB concrete marker in existing concrete.
C4FB Concrete Utility Marker Installation Instructions