Check the listing for details. Fret Glo "Fret position markers for Guitar or Bass". Color: Multicolor, Condition: New. Listed at 9.99 USD. Available colors: Neon lime greenAvailable colors: Neon lime green <-- These glow the brightest.Neon mint <--------- These glow the brightest.Neon yellowNeon orangeNeon peachNeon pinkLilac purpleMatte black <--- Super thin but don't glow.Matte white <--- Super thin but don't glow. Sizes: Small circle - 5/32" - 3.81 mmMedium circle - 1/5" - 5.08 mmLarge circle - 1/4" - 6.35 mmSemicircle - various sized semicircles for any guitar/base. Frequently asked questions: Q. How do you install them?A. Just like you would any decal or sticker. Thin removable vinyl between a release liner an clear transfer tape. Q. How many markers per order?A. 12 markers per order, enough for a 24 fret instrument. Q. How long do they glow for?A. About 15 to 30 minutes. Investing in a budget class-a UV light will give you the best results. Q. How long will they last?A. I've had the same set on my guitars for over 6 years. Q. Are they easy to remove?A. All my markers use a removable non-permanent adhesive. Hi my name's Jayson. I created Fret Glo markers to fill a need I had when playing guitar and bass. I'm legally blind and can have some trouble when adjusting to different scale lengths, or playing in dark venues. I wanted something That's unintrusive, and removable. Fret Glo is a one-man operation. If you have any issues or concerns. Just shoot me a message and I'll be more than happy to assist. Thanks again for your time and interest.