The Grant Instruments AQBT12 clear polycarbonate base trays can be used with Grant Instruments 12 liter unstirred water baths (JBA12 US, JBN12 US, SAP12 US and SAPD US), all sold separately. AQBT12 comprises two separate base trays that can be used alongside each other within a compatible water bath. AQBT12 base trays are supplied as standard with new JBA12 US, JBN12 US, SAP12 US and SAPD US water baths, but can be purchased here separately as a replacement. Use of a base tray is required if flat-bottomed flasks are to be placed directly on the base of an unstirred water bath. Its use promotes thermal convection and optimal temperature uniformity. When combined together the product dimensions are: 18 x 29.5 x 25.0 cm (H x W x D).