Delta 81T231BTA-20-38 Commercial Chrome H2Optics Exposed Flush Valve. Delta's Line of Commercial Products are an industry leader in the Bathroom Faucets, Shower Fixtures and Bathroom Accessories. The large line of Commercial Grade products are designed to withstand the every day wear and tear, and last for years to come. These products are ideal for hospitals, schools, and other high traffic applications. This Delta 81T231BTA-20-38 Commercial H2Optics Exposed Flush Valve features a battery powered design with a H2Optics Sensor. This Automatic Flush Valve features s durable brass constructed body with Chrome finish.