Berntsen offers the following styles of aluminum concrete survey markers for use in concrete or rock:

"C" style (US Army Corps of Engineers Type 1 Disc) has the classic 3" (76mm) long split-style tapered stem. It is available in 3-1/2" (89mm) or 4" (102mm) diameters. Orbital formed from solid 6000 series aluminum bar.

For smaller marks use the "CD" style 2" (50mm) diameter marker has a 3 /4" (19mm) diameter x 2" (50mm) long stem and is notched to hold firmly in concrete or rock. Orbital formed from solid 6000 series aluminum bar. It is also available as a leveling mark with a raised datum point (with recessed center) for precise monitoring (model CD2L).

The "RT" style is a variation on the concrete disc theme and is available in a 3-1/2" (89mm) diameter. The RT1 offers more resistance to twisting and features four legs. Orbital formed from solid 6000 series aluminum bar.

The CAPMAG ceramic magnet can be used with concrete markers to assure easy detection of the mark by a magnetic locator. Dimensions are 1/2" (13 mm) in diameter & 1/4" (6 mm) long.  Can be located up to four feet deep with a magnetic locator.

Preview  

A = 4" (102 mm)
B = 23/32" (18 mm)
C = 3" (76 mm)
D = 7/8" (22 mm)