This plastic spile is designed to be used with plastic sap bucket. The hole in the top of the spile top works with the metal hinge on a plastic bucket lid. The metal rod slides through the hole to secure the lid over the bucket. The bucket is hung on the hook, which is strong enough to hold the weight of a 3-gallon bucket full of sap. The smaller 5/16 inch size is healthier for the tree than 7/16 inch. 10 per package.