This mini polyphosphate dosing unit with a 1/2-inch by-pass fits onto boilers and water heaters to protect plumbing systems from limescale build-up and corrosion. It is a compact in-line device that treats the water as it passes through.

• Suits boilers and water heaters
• 1/2-inch connection with by-pass
• Protects against limescale and corrosion