The Drift Control Original Series Drift Sock slows your boat's drift or trolling speed, allowing better control of lure speed and presentation. The Lindy Original Series Drift Socks' lightweight ripstop nylon construction allows for quick drying and compact storage. One-inch nylon straps offer added support, ensuring years of tear-free usage. The Original Series sock has flotation material in the upper cylinder and is weighted in the bottom, allowing for quick opening and resistance to rotation. Model: DCSS Size: Medium - Opening: 40 in. Size: Large - Opening: 50 in. Size: X-Large - Opening: 60 in. Boat Length (ft.) Wind Sock (in.) 14 or Smaller Heavy/Strong Wind 36 - 42 16 - 18 Moderate Wind 36 - 42 16 - 18 Heavy/Strong Wind 48 - 50 20 or Larger Light/Breezy Wind 36 - 42 20 or Larger Moderate Wind 48 - 50 20 or Larger Heavy/Strong Wind 60