Durable protective molded rubber bow roller, to protect your investment, and hold your boat in place. Tired of replacing or cleaning scuff marks off your boat? Hull Sav&';r is the name to go with, because it actually lives up to it&';s name. Try one out, you wont regret it! Shaft Size 1/2" Poly bow roller assembly includes end bells and bolt New poly vinyl rollers Long lasting Will absorb shock Cut resistant Will not mark or mar your boat Tie Down&';s enhanced formula for PVC far outperforms traditional polyurethane products