Size refers to outer diameter X length Feature: Easy to install and convenience use for outdoor Please Note : Please select the appropriate size of acrylic pipe, especially the size of inner diameter and outer diameter. Acrylic pipe can be used in water cooling system. It should be noted that the silicone tube insert(prevents kinks) and professional bending tools are required for bending Clear Acrylic tubes are widely used: Hydroponic planting frame, aquarium supplies and fish tank adapter, water connections, home diy Material: which has good stability and high hardness. It has good impact strength, aging resistance, and wear resistance, is not easy to break, and is suitable for indoor and outdoor use, Manufacturer: ZIUBMVDYC