Material: Aluminum & Acrylic. Size:As the picture show Package Include:4 x knobs(As the picture show.) Fits for Les Paul style guitar and most similar guitars. Use: Knobs fits 18 fine-spline split-shaft pots. Knobs only fit metric 18 coarse splines split shaft pots with 5.8mm diameter. If there are 10 splines on each side, your pots will need 24 fine spines knobs. If there are 8 splines on each side, your pots will need 18 coarse splines knobs. Package includes: 2 x Volume knobs, 2 x Tone knobs. Note: Due to the influence of shooting lighting/computer phone monitor, there is some color difference between the image and the actual product. There may be a dimension measurement error of ± 0.5mm.