Artist pack of 48 corner wedges is for 6 art frames, 2 wedges per each corner. These are made from heavy duty plastic and unlike wooden wedges these will not break or split when tapping them into your frame. Can be easily taken out and reused over and over again. Simply put 2 of them inside miters of your frame and tap each one with a small hammer until the canvas is taut to your liking. Each key is 1/8 of an inch thick or 3.2mm