In-line tee valves are used in intervals along a hose line and allow you to attach additional 1" branch lines which are individually controlled by a valve. 
Cast aluminum for superior performance in extreme conditions
Hard anodized for rugged durability
Stainless steel stem with high pressure O-rings to ensure a seal.
Compact design that is easy to use with a gloved hand
 
Thread Type Guide:
F - Female
M - Male
NH/NST - (National Hose / National Standard Thread) - Both are the same for fire hose threads and are the most common.
NPSH - (National Pipe Straight Hose) Regular straight pipe threads.
 
These tee valves fit directly onto standard NST thread fire hoses and outlets (most common for fire hoses in the USA).
Note: You can connect this tee valve to a different size hose, outlet, or thread type, by using an adapter.