Delta R2570-MIXLF Commercial Thermostatic Mixing 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 R2570-MIXLF Commercial Thermostatic Mixing Valve senses the outlet water temperature and reacts to maintain a constant delivery temperature even under changing flows or variations in supply temperatures or pressures.