The Fireplace 9" is the highest quality medium duty firebrick that can be used for pizza ovens, pottery kilns, fireplaces and temperatures less than 2000F/1200C. The Medium Duty Fireplace brick conforms to ASTM Specifications C-27 Class 4.1.4 and 4.1.5 for Medium Duty and Low Duty respectively and C-1261-98 (which includes C-24 and C-67), as well as, C-16, C-20, C-24, C-38, C-113, C-133. The dimensions of the brick are: 9" x 4-1/2" x 2-1/2"(inch) or 230 x 114 x 64mm. *Please note 45 bricks can fit per pallet.