Dimensions: 5-1/2" x 5-1/2" x 1/2" 140 x 12.7mm.
Fits RapidFire and Hot Box Kilns. Made from cordierite, a low thermal expansion calcine type of refractory clay. Has heat tolerance of over 2150 degrees F. Smooth and flat, will accept shelf primer to keep glass from sticking to the shelf.