Miller DuraHoist Confined Space Manhole Collar Cotton Swinging hinge points — Allows

Swinging hinge points — Allows you to find the most comfortable position on the back of your head

Quick-close rubber tab with hook and loop closure

Exceeds the ANSI Z87

You can then scroll through the peaks to see the readings

Miller DuraHoist Confined Space Manhole Collar Cotton Swinging hinge points — AllowsThe Miller DuraHoist manhole collar is designed to easily and quickly mount to manhole collars. Simply slip the collar into manhole, tank hatch, or other opening and then mount you DuraHoist mast. That's all it takes and your ready to go. The DuraHoist collar is available in a variety of sizes: 17. 5 in. (. 44m) Manhole Collar for use with 18 in. to 20 in. 19. 5 in. (. 50m) Manhole Collar for use with 20 in. to 22 in. 21. 5 in. (. 54m) Manhole Collar