Individual Items › Round Tool Holder Image 1 of 2 Image 2 of 2 Round Tool Holder from $20.00 The Round Tool Holder comes in a single or a double version and is for tools that have up to a ONE inch O.D. Size: Select Size Single Double Quantity: Add To Cart Added! The Round Tool Holder comes in a single or a double version and is for tools that have up to a ONE inch O.D.