1) The material is iron with black powder coating,  it will not rust.

If have rust, we will give new bracket, please rest assured;

2) Used to mount led work light: SS-1004

3) One full Set include 2pcs;

mount bracket clamp

Universal Vertical mount bracket clamp , This highly efficient add-on will allow you to mount the Rigid LED Light at any angle so you can direct the light output where it is needed most. The part features sturdy construction to provide the strength required to hold the light securely in place.