Twinklefilter Pack of 13 Wooden Clay Sculpture Knife Pottery Sharpen Modeling Ball Stylus Polymer Tools Set Wooden Clay Sculpture knife Length: Approx. 14.5-15.6cm Double ended Larger ball :Total length: Approx. 5.6 inch; Ended Ball Diameter: Approx. 2mm Single ended ball :Total length: Approx. 4.8 inch; Ended Ball Diameter: Approx. 3mm