There are many types of swivels designed to match specific fishing needs or those with numerous components extending from the basic swivel itself. However, for the sake of simplicity, the two most common basic level swivels are ball-bearing swivels and barrel swivels
Barrel Swivels
The general design of a barrel swivel is a central hollow brass, stainless steel or nickel barrel (hence the name) that has been swaged around pins that are bent into eyes for attachment to other terminal tackle pieces like snaps, locks or rings. Barrel swivels are probably the most popular form due to their low cost and wide range of sizes that cover seemingly all of the fishing needs.