The MB101B is a 38mm Stainless Steel Wrap-Around Bullbar Bracket in a Black Finish.
This bracket is also available in various sizes and available in a stainless steel finish:
38mm (MB101B)
45mm (MB102SS or MB102B)
50mm (MB103SS or MB103B)
63mm (MB104SS or MB104B)
76mm (MB105SS or MB105B)