3D printed Casing and acrylic Lid and red acrylic cover. 
Has 2 Test Tube sockets with gates that slide down into place, as well as a Tube socket with a gate, as well as additional cover slots. 
I can print additional sockets with gates if needed, $4.50 each, the cover slots are $2.50 each.
Here is an example of the 3 slot options:  https://photos.app.goo.gl/Gm3ZVjBeevgWgRD98