This is the XS Scuba Finger Spool with Stainless Steel Clip Scuba Diving Features: Available in three sizes Spools are injection-molded with glass-filled nylon #24 hi-viz yellow nylon 16 strand line (breaking strength 120 lbs / 55 kg) 4 stainless steel doublender bolt snap with 18-8 SS internal springs XS Scuba&';s Finger Spools come equipped with a durable corrosion resistant 4" (10.2 cm) stainless-steel double-ender bolt snap with 18-8 stainless-steel internal spring. "