Specialty Archery’s redesigned Glow Ring (GR) now has easily replaceable fiber, and an easily replaceable Glow Pin (GP), allowing the archer to customize both fiber color and pin diameter. Redesigned Glow Pin protects fiber from damage in the field. Fiber colors are easily interchangeable without the use of tools. Clear fiber shroud allows maximum light transmission to the fiber, allowing for maximum pin brightness. Available in .010”, .020”, or .030” diameter. Each Glow Ring includes 8” of red, green, and blue fiber optic. Glow Pins are also interchangeable, allowing the archer to change pin size without the need to purchase an additional Glow Ring. - See more at: http://www.specialtyarch.com/products-page/scopes/super-d-scope/super-d-1011-glow-rings/glow-ring-for-super-d-scope-1011/#sthash.j9qxjUit.dpuf