The new and improved Butt Loks feature a hard plastic skeleton with a soft and durable rubber on the mold. When properly sized to the rod, these securely lock the butt of the rod blank. Available in 3 standard sizes (Small, Medium, and Large) to fit full/synthetic cork double guns and from the thinnest 10-foot blanks up to the most powerful 13-foot blanks in shortened wrap or heat-shrink handles. The Duo model is for the angler who switches from full cork/synthetic cork to shortened or fully heat-shrink handles. Supplied with a rubber O-ring for precise alignment on buzz bars.