4" Spring Clamp: The 4" Spring Clamp is a big help for all Basket Weavers. The Clamp keeps strands of material tight while weaving. Soft rubber tips protect your weaving material while steel keeps it taunt. Easy to squeeze clamps are a third hand in the weaving process. Can be used with all types of basket projects, and seat weaving projects. Spring Clamps are great for any craft or DIY project. 4 Inch clamps are used to hold a Nantucket Basket rim in place.