FUAUFAS Stratus Precision Rain Gauge with Mounting Bracket (14" All Weather)

Is there a measurement on the outside tube for the accumulated inches or do you have decant from the outside tube through the inside tube to measure?

What is the maximum capacity of the gauge in inches of rain? I'm guessing about 13".

Why is the top of the rain gauge so loose? Does it screw on it feels like any wind will take it. I am confused please help.

How many ounces or ml does this hold? (I'd like to keep the collected water as samples).