Features The wheel surfaces are made of thickening rubber, which is deformation and non-slip. Rubber wheel, wear-resistant, good friction. Can be used for turning encoders to create wheel encoders. Aluminum alloy bracket, strong structure, durable in use. Good rigidity, stable operation, easy to use. Specification: Material: rubber, aluminium alloy. Model (optional) circumference hole diameter EW-002 200 mm 6 mm EW-011 250 mm 6 mm EW-003 300 mm 8 mm. Features: The wheel surfaces are made of thickening rubber, which is deformation and non-slip. Aluminum alloy bracket, strong structure, durable in use. Good rigidity, stable operation, easy to use. Rubber wheel, wear-resistant, good friction. Package list: 1 x encoder measuring wheel Package List