Effective Joining - Use the Pisces Inline Pond Hose jointer to connect two pieces of hose with a size of 20mm to 20mm (Internal dimensions) in your pond filter set up. Barbed fitting - Each connector has a barbed texture edging that allows for a secure grip and fit onto the pond hose. Strong Materials - Made of strong plastic material, the reducing fitting adapter is made to last and is up to various tasks around the garden and home. Multiple Uses - Can be used on Pond hosing, hosepipes, pipe tubes, irrigation systems, agricultural or lawn equipment, and hydroponics. Ease of Installation - The joiners are simple to install onto pond hose and are ideal for corrugated types. Provided with 2 Double Wire Hose Clips.