This Case Holder Adjusts Tension By Means Of A Spring Loaded Screw, And You Can Hold Your Work Between The Four Movable, Adjustable Plastic Headed Pegs. You Can Place The Pegs Wherever Need To Hold Even Oddly Shaped Pieces, And The Plastic Won't Allow Any Scratching. While You Work On Your Piece, It Can't Move Around.* Length 2.5", Height 1", Width of one arm 0.5" * Hole Size: 5mm , Jaw Capacity : 1.2" * Has 20 Holes for setting in different positions for different cases * Great for watch repair, holding watch cases, work materials and tools * Plastic posts to prevent marring