Parameter: 4 Pieces Of Glass Clamps, Size 27.9*28.8*18.8Mm (Lxwxh), Suitable For 8-12Mm Glass. Material: The Glass Clamp Is Made Of Zinc Alloy, Looks Sleek With Polished Surface Treatment, Ensuring Quality Reliability And Longevity In Wet Weather Durability. Adjustable: Each Glass Clamps Bracket Comes With 1 Rubber Gasket And A Micro-Adjustment Screw To Make The Sturdy Bracket And Provide A Solid Grip On The Glass.Adjustable To Fit Glass Shelf Of Different Thicknesses. Easy To Install: Screw To The Wall With Fixings Provided, Then Simply Adjust The Space Between The Jaws To Clamp To The Shelf By A Screw At The Base Of The Bracket.The Screws Are Invisible After Installation, And They Are Beautiful. Widely Used: Ideal For Bookshelf, Exhibition Stand, Garden Shelf , External Wall Brackets And Bathroom Shelf Etc.