Please use these as a substitute for split rings and swivels. There are 100 pieces in a pack, and the sizes are shown in the photos. Have you ever experienced line breakage when using fluorocarbon main line? I love fluorocarbon main line because it's UV resistant, sinks quickly, and has little stretch. However, I've had line breakage, so I've been using cushion rubber instead of split rings. Since then, I haven't had any main line breakage, and I've had fewer leader breaks. Also, I think there's less line breakage even with thin leaders (though it might still break if it rubs). Because they are made of rubber, if you're using a knot like the overhand knot for your leader, pass the leader through the cushion rubber at least twice. If you only pass it through once, the cushion rubber may break. I've never had it break when using a loop knot. Shipping will be via the trackable and insured "Nekopos" service. Delivery is expected the day after shipping for the Kanto, Chubu, and Kinki regions. Please note that returns and claims are not accepted.