I ordered 1/4 NTP and what I received is much smaller. Have a look around - the max outside diameter should be 0.54" and they are 0.52". It may not seem like much, but it's too small for NPT. Judging by the reviews, some of them are good and some are bad. I definitely got sick and they will be back.
12V Brass Solenoid Valve, 3/4" Electric Air Valve For Water, Air, Gas, Fuel And Oil - Normally Closed By Beduan
10 Review
6 Pack Miahart Adjustable 304 Stainless Steel 4 Inch Hose Clamp Duct 91Mm-114Mm Worm Gear Pipe Clamp For Automotive, Mechanical Agriculture.
18 Review
Joywayus 5/8" ID Hose Barb Hex Union Brass Fitting Water/Fuel/Air With 10 Stainless Steel Clamps (Pack Of 5)
13 Review
Upgrade Your Draft Beer Kegerator With The TerraBloom CO2 Keg Pressure Regulator - Dual Gauge Heavy Duty Unit With Safety Features
16 Review