revocable living trust
Open box because you can put stuff in, take things out, amend it, change it, terminate it but it holds all of your things neatly. I analogize a trust to a little red wagon that I had as a kid, and that I bought at Tomlinson's for my kids when that was their thing...
When we were little, we put things in, took things out, whatever we wanted and we had the handle when we wanted to pull it and when we didn't we could give that handle to someone else for them to pull around. And in that handle are instructions so whoever is pulling it knows what to do with what is in the wagon. Each asset you have is a box. Neatly stored in the wagon. If we didn't have the wagon, if we slipped and fell, instead of all our boxes falling all around us, they are still in the wagon and now someone else has the handle, the instructions.