Handmade shift knob made of POM (polyacetal) resin. Product Name: Made of the same resin as Duracon, it has excellent mechanical strength and sliding performance, and is used as a material for gears, bearings, food processing machinery, and parts for medical equipment that require hygiene. It is also resistant to heat and does not seem to get so hot that you can't touch it in the summer. The specific gravity is 1.41, so it is considerably heavier than wood. Please check if the size and pitch of the threads on the mounting part match before selecting. The thread size of the mounting part of this shift knob is 12 x 1.25mm, so the following diameter conversion adapter can be used. 《 About the Mounting Diameter Conversion Adapter 》 If the thread size on the shift lever side is 10x1.25, 10x1.5, 8x1.25, 6x1.0mm, or 12x1.75mm, it can be installed by using the separately sold diameter conversion adapter below. 12x1.25mm (knob side) → 10x1.25mm (lever side) 12x1.25mm (knob side) → 10x1.5mm (lever side) 12x1.25mm (knob side) → 8x1.25mm (lever side) 12x1.25mm (knob side) → 6x1.0mm (lever side) 12x1.25mm (knob side) → 12x1.75mm (lever side) (←This conversion adapter will be 23mm longer) 《 Delivery Method 》 Free shipping, but it will be by regular mail. 《 For other sizes and materials 》 We also accept custom orders to match your desired thread size, material, and dimensions. If you wish, please contact us through the inquiry form on the HP of "Wood Workshop Craft Miya". (Please note that exchanging information about other products in the comments section of this product is prohibited.)