Premium Stainless Steel Construction: Made from sturdy 304 stainless steel, these snapping buttons resist seawater and oxidation, ideal for marine environments like yachts and boats while maintaining shines longer than ordinary copper buckles. Secure Fastening systems: Each set includes 15mm auto screws that firmly attach to wood, canvas, and other materials without loosening, perfect for sail covers, awnings, and frequent use outdoor applications requiring strong pull resistance. Accuracy snapping Mechanism: standard 4 part snapping structure with smooth operations crisp clicking action without jamming, maintains springiness after repeated use, and has burr release surfaces to protect fabrics from damage. Easy Installation set: Comes with included setting punching tool for hassle release hole punching and crimping, enabling quick installation by beginners or professional for both craft repairs and bulk projects. Versatile Marine & Outdoor Use: 15mm size fits most marine canvas, tents, sunshades, and leather crafts, making it essential for yacht maintenance, camping gear repairs, and handmade fabric/leather goods reinforcement.