Ratchet Buckle Clasp is an ideal Wetsuit watch band buckle. The ratchet theory extension mechanism is of great importance for both convenience and safety. Super-O Boyer watch bracelet is composed by 3 flat and solid 316L stainless steel units and a curved solid end piece perfectly fit Seiko SNZF17 Sea UrchinX. Screw-in adjustable details instead of flimsy pins to keep its solidity and stability. This item includes one pair of FAT spring bar (eg. generic Seiko Dia. 2.5mm spring bar) to ensure a more secure connection. Tapered 22mm lug into 20mm buckle size. This Super-O Boyer watch bracelet is a good choice of Seiko replacement watch band for your SNZF17 Sea Urchin models.