The US or UL sized tubing is slightly larger than our MM or Metric sized pond tubing.
2"x50Ft Flexible Non-Kink Water Garden Pond Tubing – UL Size This tubing works best with Alita, Atlantic Water Gardens, Aquascape, Little Giant, Oase, Pondmaster and Savio Products. If you are not certain which size to order, it is usually better to order the UL size and build up your fitting or pump outlet since the MM size is smaller and may not fit your application. This hose is designed to be used with barbed or insert fittings and appropriate clamps..