The DGX Gears Glow-In-The-Dark Finger Spool is made of luminous ABS plastic loaded with {100 ft | 30 m} of #18 ~1.5mm braided nylon line also impregnated with phosphorescent pigments and includes a 3.5 inch stainless steel double-eye bolt snap. To help prevent twisting, a stainless steel line swivel is attached between the end of the GITD line and a leader loop of black line. Approximate dimensions of the spool are a diameter of {3.0 in | 7.5cm} and width of {1.5 In | 3.5 cm} with a center {1 in | 2.5 cm} finger hole.

The phosphorescent nature of the material gives the spool and line the ability to absorb light and then slowly emit this absorbed light for a period of time. Due to this luminous property the spool and line can "glow-in-the-dark". The emitting time and brightness varies widely and depends upon a variety of factors including the amount of light previously absorbed, visual acuity of the diver, distance from the phosphorescence and amount of surrounding light.