Size includes 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm, 5.0mm, 5.5mm, 6.0mm. Product material: TPR mixed PP soft handle + aluminum hook head Durable in use,smooth to touch and easy to operate. The ergonomic shape grip that developed independently is very comfortable to hold. Can meet your knitting need fundamentally, great tool for you to knit sweaters.