Joints are used to connect the Growth Modules to each other. Joints come with (2) 2 in or 3 in UC Spin Tight Bulkheads pre-installed and are included with all Under Current Systems. Joint – Complete: 18 in Plant Centers, 2 in UC Spin Tight Bulkheads, 8 Gallon Systems. Joint XL – Complete: 25 in Plant Centers, 2 in UC Spin Tight Bulkheads, 8 Gallon Systems. Joint XL13 – Complete: 30 in Plant Centers, 3 in UC Spin Tight Bulkheads, 13 Gallon Systems. Joint XXL13 – Complete: 40 in Plant Centers, 3 in UC Spin Tight Bulkheads, 13 Gallon Systems. Made in California.
