This is a set of Dubro heavy-duty ball links for use with 4-40 threaded rods.
Features:
Includes: Twelve each of heavy-duty ball links with brass swivel-balls, beveled brass swivel-ball stand-offs, 4-40 x 5/8 hex-head mounting screws and #4 lock nuts (metal construction with nylon insert)
Requires: 3/32 allen wrench and 1/4 open-end wrench or nutdriver
Specs:
Ball Link Length: 27mm (1.063)
Standoff Height: 3.2mm (0.125)