Are you worried when you carry milk crates into your spot? This nifty stool will fit right in your back pack, or attach to it on the outside. At their most compact point, these stools are under 3" thick by about 10". At their most extended point, they can open to a height of just under 18" (17.72"). These can handle a surprising amount of weight (330 lbs). However, there are a few catches.

Stools are recommended for walls or chill spots with level ground, or freight spots with grass or level ballast. These should not be used on an angle, and work best when extending about 3/4 of the way (just beyond milk crate height). These are highly portable, collapsible and don't take up a lot of room. They are also cheap enough that they are easily replaceable.

Disclaimer: use at your own risk. This product is designed for use on level surfaces and as a sitting stool. Available in solid black and solid blue.