1/2" coupling allows you to connect two pieces of tubing together. Also used for repairing your drip irrigation tubing, cutting the bad part out and splicing it together with the coupling.
Compression and threaded on all sides having, .580 i.d. compression on the inside and male hose threads on the outside.
By using a 141 cap on the end of the coupling, you can use these two items to end your line.