Synergy Swim Socks Neoprene Swim Booties PROVEN TECHNOLOGY EQUALS SUPERIOR PERFORMANCE - 2.5mm insulating neoprene booties for superior heat retention. EXCEPTIONAL FUNCTIONALITY  Long hose with smoothskin lining greatly reduces water entry. SUPERIOR COMFORT - Durable and flexible swim socks with silicone thread helps keep your swim booties in place. CUSTOMER SATISFACTION - 30-Day Guarantee: If you are not 100% satisfied within 30-days, send it back for a full refund.