tub·ing 
/ˈtu:bɪŋ, Brit ˈtju:bɪŋ/ noun
/ˈtu:bɪŋ, Brit ˈtju:bɪŋ/ noun [noncount] 1 : material in the form of a tube : a series or system of tubes
▪ The fluids travel through flexible plastic/rubber tubing. 2 : the activity of riding on an inner tube over snow, down a river, etc.
▪ We go tubing on the river every summer.
▪ The fluids travel through flexible plastic/rubber tubing.
▪ We go tubing on the river every summer.
