This plastic tap nipple is suitable for an outdoor faucet with an internal thread and a diameter of 1/2 "inch. tap nipples come in different sizes, therefore before you buy a nipple you better measure the thread of the tap. Here, 21mm is 1/2" inch, 26.5mm is 3/4" inch and 33.3mm is 1" inch. in addition, check whether the outdoor faucet has an internal or external thread. for an outdoor faucet with an internal thread, use an external nipple and for an outdoor faucet with an external thread, use an internal nipple.
