Water Barrel Connector for linking them together.

Standard Aqua Roll Connector kit (for linking 2 Aqua Rolls together). My design uses Hozelock type connectors to connect the hose and I use "certified Blue Food Grade Pipe", others don't to save money, My Aqua Roll connector is "Made In Kent" by GuessWorks2, so take the Guess Work out by buying GuessWorks2 original products.

eBay