Elkay Quartz Classic ELG1515BQ0 Bisque Single Bowl Dual Mount Sink DUAL MOUNT: Versatile design allows the sink to be installed as a top mount or undermount SINGLE BOWL: Bowl gives you uninterrupted space for washing and stacking dishes or other household tasks QUIET: Sound-deadening material minimizes sound and vibration for a quieter time at the sink DRAIN OPENING: Sink drain opening measures 3-1/2" CABINET SIZE: Minimum cabinet size for this sink is 21"