This is what Dive Rite say:
"In the early days of cave diving, reels were not available to buy off the shelf. Divers used anything they could, including empty electrical wire spools. When exploring, divers would pay out the line and if they didn't empty the spool it would be left in the cave for the next dive. The spools came in various sizes and North Florida cave diver, Bill Hogarth Main, popularized smaller spools for safety and jump reels. Today, our 125-foot Finger Spool is often used for shooting lift bags as well as a safety reel. Small and low-profile, a spool fits nicely out of the way in a pocket or clipped off to a D-ring. The holes in the side allow for clipping in the double ended snap anywhere along the perimeter of the spool to keep the line tight when not in use. Made of ABS plastic, finger spools are simple to use and virtually indestructible in the water."
Dacron line does not stretch, keeping tension firm (RE4920)
Uses #24 braid line giving 220-lbs of breakage strength.
Injection molded polycarbonate spools resist breakage and cracking.
Marine grade stainless steel double ended bolt snap is corrosion resistant.
6 oz (170g)