Do you have a first stage regulator that has 1/2"-20 low-pressure ports and want to attach a standard 3/8"24 low-pressure hose? This adapter allows the connection of a standard low-pressure regulator Hose or inflation hose (3/8-24) into a large size regulator first stage low-pressure port (1/2-20). This durable corrosion resistant black finish chrome plated brass adapter with Viton O-ring is what you are looking for. Designed for low pressure only below 200 psi (13.8 bars) and factory cleaned so it's ready for Nitrox this adapter makes a great save-a-dive-kit item.