Y adapter for fresh water at park water supply post?

I use a "y" on my water line. Handy to have a 2nd hose to put out fire or hosing off a grandchild. Some "y" have small passages/valves. To ensure a good water flow I'd look for one with a passage as close in size to the hose as possible. Lowes I believe has one with some pretty large passages. Larger than the others I've seen. Was around $13.