The YakAttack Stealth Pulley is designed for use with anchor trolleys but great for many other applications and is engineered to be the most quiet, low profile, shielded, and snag free pulley created for kayaks. Teflon infused, wear resistant nylon rollers offer quiet, smooth operation and extreme durability for a lifetime of use. The shielded, snag-proof housing protects the rollers from docks, stumps, and other obstacles you may encounter on the water.