Links. 2 required. Used with 2 each - #20413 1 3/4 Tube Clamps and #28024 1 1/2 B Clamps and 4 each #30052 1/4-20 x 3/4 Carriage Bolts, #42550 1/4-20 Keps Locking Nuts. Secures #927808 Center Section with Splice to #27810 Bottom Section. Also available in #900011 CP24 Clamp Assembly.