This is the Plastic Line Arrow Pointers for Cave Diving Single OR Pack of 25 Markers Features: Plastic line markers Available in Hi-viz Yellow or Glow in the Dark Size 2.5 x 1.5" Will work on lines 1/8" - 3/16" Available in single arrows or Pack of 25 Line Arrows are used by cave and wreck divers to point in the direction to go. Line Arrow attaches to the safety line placed through the cave tunnels or passage ways of a wreck keeping the divers safe even if they disturb the sediments and visibility. "
House of Scuba
