Blackburn FBS4H130A1-24 FLEX BRAID 4 9/16H 1/4 X 3 X 24 IN

It's a flat, flexible tin-plated copper braid shunt used to carry current across a joint that has to move, flex, or absorb thermal expansion, typically on switchgear, disconnect switches, bus runs, and substation connections. The braid replaces a rigid bus link where vibration or movement would otherwise stress the joint. Four bolt holes, 24 inch overall length, sold each.

It is built to CEI60694 and IEEE/ANSI C37.34-1994, the high-voltage switchgear and air disconnect switch standards, so it will satisfy a drawing that calls out those references for flexible connectors. Country of origin is the United States, which also matters where domestic-content language is in the contract.

Tin plating over the copper is what makes this acceptable against aluminum bus, since the tin barrier limits the galvanic action you would get from bare copper on aluminum. Clean both pads, use a joint compound suited to the metals, and torque to the bus manufacturer's figure. Bare copper braid is copper-to-copper only.

Braid is the choice when the joint has to move: thermal growth on a long bus run, vibration from a breaker or transformer, or a switch blade that travels. A flat braid flexes in the thin direction with very low mechanical resistance while still presenting a lot of surface area for current, which round cable of the same rating cannot do in a confined switchgear cabinet. Where nothing moves, a rigid bus link is cheaper and simpler.

24 inches is the overall length of the assembly including the terminal pads, so the free braid between pads is shorter than that. Measure your pad-to-pad gap and allow slack for the movement you are accommodating rather than pulling the braid taut.