Renzetti offer a full line of bobbins. To accommodate different tying needs, we feature bobbins with varying combinations of tube lengths and diameters. The standard length tube is 2-inches, the extended length version is 2 3/4-inches. The small diameter tube is 3/32-inch and the large diameter tube is 1/8-inch. With the exception of the Ultra Midge Bobbin and Lead Wire and Tinsel Bobbin, we use ruby tips that make for ultra smooth thread delivery and excellent wear resistance. Customer feed back has led us to redesign the bobbin balls. Our unique tapered protrusion insures maximum thread spool retention.