One thing we enjoy about the rail trail is the fact that you can walk or ride without worrying about vehicles, except at road crossings. It is a wonderful safe place to ride with children. However, should the worst should happen, you will find these emergency location signs frequently along the trail. This allows you to give emergency services an accurate location so they can find you as quickly as possible. Hopefully you wont need them, but its reassuring to know they are there.
congratulations Cachemonsterhunter FTF
You are looking for a screwtop tube.