WEEB Bonding Jumper 8.0, 30020121, Wiley

WEEB-8.0 Bonding Jumper is used to electrically bond mounting rails together at a splice. Use one at every splice.

Long rails for roof mount installations are sometimes constructed from two shorter rail sections with a mechanical splice. It is then necessary to also make an electrical splice, which can be done with a WEEB Bonding Jumper. 

For extremely long rails, the manufacturers generally recommend that the mechanical splice be connected at only one end. This allows for thermal expansion. When installing the electrical splice on spliced rails that require provisions for thermal expansion, install the WEEB Bonding Jumper with some slack in the tin-plated copper braid.