SHT1/28 Aluminium blocks. 6 place for 28mm tubes, hole size 28.0mm diameter x 47mm depth , for use with Stuart block heaters. Manufactured from anodized aluminium and all with a separate hole to accommodate a thermometer if desired. All blocks with the exception of BH/15146 and BH/15148, have dimensions, (w x l x h) of 75x95x50mm and can be used in any combination.