The 519-BKBA Stainless Steel Bolt Kit is used to attach standard Zeagle Bladder Assemblies to the Zeagle backplate. The bolts go through the stainless steel tri-bars on the bladder assembly that normally hold the strap that fastens the bladder assembly to the vest section of the Zeagle BC. The tapered head of the bolt fits flush in the tapered holes in the backplate. There are two rows of holes in the backplate. The two outer rows are used to keep the bladder assembly spread wide if double tanks are used. The two inner rows are used to keep the bladder wings closer together in single tank applications.