Gorgeous set of IST rubber rocket fins, #1 military use, durable and well-made, size large (L) - US 6/7, EU 37-39. According to manufacturer website product description:

• "Traditional rubber fin with proven design.
• By combining features such as special blade curvature, varying degree of flexibility and structural ribs, the product is positive forward thrust with spring-like effect.
• The open vents efficiently channels the water flow to give added energy saving effect.
• Stainless steel spring fin strap compatible."

 Stock photos pictured, same as my pair, in great shape!