Delta Diamond Seal Technology Faucet Cartridge. For Use With Delta Single Handle Kitchen And Lavatory Faucets Featuring Diamond Seal Technology (DST). Unique technology requires no lubrication or seal replacement. Long-lasting performance with durable, corrosion-resistant construction. Red tab on the back top of the cartridge is an easy to set built-in temperature stop. This allows you to set the handle motion for full flow hot water to a 50/50 hot/cold mix, helping to reduce the risk of scalding.