G2. 1/4" plastic cap for backflow assembly test cocks, ~50 count.

G2 1/4" plastic flare cap for test ports (1/4" SAE Flare), approx. 50 Count.

It's the law in many places to cover the test ports and test cocks on backflow assemblies. These caps make it easy and inexpensive.  

Threaded cap stays on better than press caps used to cover test ports to keep them clean between tests and comply with the law.