Delta 063139A Commercial Adapter With Flow Control (0.5 Gpm). 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 063139A Commercial Adapter With Flow Control (0.5 Gpm) is a genuine replacement part designed for is a genuine replacement part designed for Delta Commercial Faucets.