I love these geocaching containers. They fit right into so many areas.
We have used a tree "round" from a naturally occurring downed tree and attached a new Rubbermaid Take Along Twist & Seal 2.0 cup storage container painted an ultra flat finish. No two of our caches are the same. We craft each cache around the natural material.
You'll find plenty of room for SWAG, trackables and a log in this unit.
The dimension are for the take along twist & seal unit. There will be of course a tree round attached to the top of the unit which will increase both the depth and height.
4 1/2 in wide at top of unit
2 3/4 in wide at the base of the unit
3 1/4 in tall