Atlantic Water Gardens 3/8" x 500' Weighted Tubing 3/8" x 500' ft Weighted Tubing for Pond Aeration Includes: 3/8" insert coupling - Heavy duty nickel plated fittings, make connecting weighted tubing of different lenghts simple and secure Typhoon Pond and Lake Weighted Tubing is designed to sink fast and stay in place. High density black PVC formulation remains flexible in a wide range of temperatures for worry-free delivery of air to pond aeration systems. Product Warranty - 5 Years