The Rubbermaid 31 qt. Tandem Mop Bucket is an excellent choice for all your mopping needs. It is made of plastic and its 4 built-in casters make it easy to move. It is used for commercial mopping.. Reverse-wringing mechanism for more comfortable use. Built-in lift handles on bottom of bucket make lifting and emptying easier. Accepts up to 24 oz. mops. 4 casters for easy mobility. Sink Left to Right Length (in.): 13.25 in. Sink Type: Mop Sink. Sink Gauge: No Gauge Applicable. Included: No Additional Items Included