PM-303 Dome Marker


The PM-303 Dome Marker Post is a Cable and Pipeline Marker used as a Warning Sign to mark underground utilities such as:  Fiber Optic Cable, Gas Pipelines, Petroleum Pipelines, Electric Lines, Water Lines, Sewer Lines and all other buried utility

The PM-303 is manufactured in the USA from specially formulated resins with UV inhibitors.  Its 360˚ cylindrical shape insures that the Dome Marker Post can be seen from all angles on the ground and by air patrols.  Unlike decals or hot stamping, the ProMark graphic system has a lifetime guarantee not to fade, peel or chip.  Graphics are customized to meet customer specifications and U.S. Department of Transportation regulations.  The Marker Post is environmentally friendly and is 100% recyclable.  The PM-303 Dome Marker Post is resistant to chemicals and has high impact resistance making it the most durable way to mark underground utilities.

The Dome Marker Post has a 3.5” outside diameter and is available in all standard lengths, colors and comes complete with anchor bar.  The PM-303 is also available with a PM-TS3 Test Station or Vent.

ProMark Model PM-303 Dome Marker Post is an above ground utility marker used for identifying and avoiding major costly repairs, interruption of utility services and/or injury to those around. The PM-303 Dome Marker Post can be ordered with custom graphic information, colors and lengths.


  • * The PM-303 Dome Marker Post graphic system is_guaranteed not to fade, peel or chip for the lifetime of the_marker unlike decals and hot stamping.
  • * Colored with premium UV inhibitors to withstand harsh_outdoor environments for a minimum of 20 years.
  • * 360˚ cylindrical shape for optimum visibility both on the_ground and in the air.
  • * Resistant to solvents and stress cracking.
  • * Lightweight and easy to install.
  • * 100% recyclable


Color Chart

OrangeTelecommunication, Fiber Optic Cables, or Conduit

YellowNatural Gas, Oil, Steam, Petroleum Pipelines

BlueWater Lines

RedElectric Power Lines, Cables, Conduit

GreenSewers and Drain Lines

PurpleReclaimed Water, Irrigation

PinkTemporary Survey Markings

WhiteProposed Excavation Limits or Route



Dome Length– 20.5 ” + or – .25/ OD- 3.70″
Post Length– 55″ + or – .75/ OD- 3.50″/
Post Wall Thickness– .135 + or – .04
Anchor OD– .80” / Length- 10” + or – .25
Total Weight– 3.0 lbs. + or – .2 lbs.
Material: Virgin Prime High-Density Polyethylene (HDPE).

Specifications (Based on a 6’ Marker Post)