Note: Please allow error due to manual measurement. Thanks for your understanding. specification: Item Type: Replacement Sandpaper Discs Mandrel_x000D_Material: Stainless Steel_x000D_Size: Approx. 3 x 2.5cm/1.2 x 1.0in Features: 1Powerful Function: An effective tool for grinding, polishing, surface treatment etc. 2Made Of Stainless Steel material: Durable and able to fit the sanding pad well. 3Mandrel Handle Diameter 2.35mm: Suitable for most polishing pens on the market. 4Convenient To Use: Suitable for 2.5cm/0.98in diameter sand discs, simple and convenient. 5Nail Art Electric Sanding Head Mandrel: It can be well applied to nail art polishing heads, and it is easy to use. PackageList: 1 x Replacement Sandpaper Discs Mandrel 1 x Storage Box