1"-8 x 1-1/4" x 2-1/2" Zinc Plated Steel Coarse Thread Rod Coupling Nuts

Diameter: 1"
Diameter 2: 1-1/4"
Length: 2-1/2"
Material: Steel
Finish: Zinc
Driver Type: 1-1/4" Wrench
Thread Size: 8 (Coarse)
Style: Hex
Type: Coupling Nut

Box of 3.

A coupling nut is a long nut tapped from each side to meet in the middle, rather than all the way through in the same direction, used to connect two threaded rods end to end.