The Circular Band with Lined wishbone is a stainless steel spheres with 7 mm maximum diameter. It features a bottleneck with lock out 2mm in diameter. This design ensures the lock without forcing the knot too much and limiting the internal pressure on the rubber. The Circular Band is designed and manufactured in Italy by Cressi, an Italian brand pioneer in freediving, spearfishing, and scuba diving equipment since 1946. The product is covered by a 2-year limited warranty.