Subhanalah, I just googled your product and this is what I found:
Horizontal nipples have a unique tapered thread design that offers several installation options:
Screwed into a 1/8” pipe thread
Pushed in 1/2” tubing
Screwed into a 3/8” drilled hole in PVC pipe or a pail
Solway Feeders horizontal watering nipples are spring loaded, releasing water only when pecked at, and house a drip guard to keep leakage at bay. Each nipple will service roughly 25 poults or 6 to 8 adult birds. When paired with Solway Feeders Brass Float Valves, watering nipples can be incorporated into gravity fed watering systems.
Read more:
http://www.motherearthnews.com/home...ontal-watering-nipples-zp0.aspx#ixzz35bvCuGVj