[Dave Marx]

Bag check at the parks? No.
Bag check at the airport? You'll have to run it through the scanner.

Is the cord secure? There are metal grommets on the pouch, and the string is run through those holes and knotted on each end. The knot is small enough that the cord will pull out with sufficient effort - that's a good thing, as if it was too secure it might pose a safety problem. I use use mine constantly, and the only time the cord has pulled out is when it got snagged on something while I was walking past.

Cord length? Approximately 16" to 18" from back of neck to pouch (if you were measuring it like a necklace... total length of about 36"). There's an adjustment slide on the cord to shorten it temporarily. For permanent adjustment you could either replace the cord to make it longer, or re-knot the cord to make it shorter.