Set of 240 pieces, 6 pieces per pack, 40 packs total. Size: M (Medium) ■Product Details We have several sizes of float stoppers. When we tested the products we carry, we experimented with sizes S to L. Even when using a size 1 thin line, the M (Medium) size closed tighter than the S size due to its thicker construction. Also, when using thicker lines, we couldn't tell the difference in feel between M and L. Therefore, for lines ranging from thin to thick, the M (Medium) size, which provides the strongest grip, is the most recommended. We have used our float stoppers several times for actual rockfish fishing, and they have a relatively strong grip. They are compatible with a wide range of line thicknesses.