Thank you for viewing! This product is a ramp designed for basses with a rounded neck end, such as Jazz Basses. The ramp extends horizontally and features a protrusion to allow for playing the 1st string with a thumb down, providing the same feel as the other strings. It prevents your finger from digging in too deep and reduces snagging during thumb-up playing. The 4th string side is not sloped, allowing you to rest your thumb there as a finger rest. When ordering, please specify your desired fingerboard radius in the comments. We can accommodate 184R, 210R, 240R, 305R, 356R, 400R, and other radii. If you don't know your bass's fingerboard radius, a radius gauge tool is available for purchase on Amazon and other retailers; please use it to measure. Regarding the dimensions: * Ramp angle: 4.5° * Width: 64mm * Length: 33mm * Thickness: 6.5mm at the center The shape of the fingerboard end is rounded to match my own bass, but the shape varies depending on the manufacturer, so there may be a slight gap. The ramp surface also has the same radius as the fingerboard, so you can play without the feel of your fingers changing on each string. Spacers of 0.5mm, 1mm, 2mm, and 3mm are included for height adjustment, so please use them to your preference. This product is made with a 3D printer, and the material is PLA. Unlike typical plastics, the surface is not smooth and has small bumps. Thank you for your understanding. When installing, remove the screws holding the pickguard and attach the ramp with double-sided tape. The included double-sided tape is not compatible with lacquer finishes. Please be aware that it may also negatively affect other delicate finishes. Thank you for your consideration!