Karter Scientific 90 Tube - 13x100mm Clear Plastic Test Tube Set with Caps and Rack - 207D3

I dont understand the dimensions. How long is it? Would the width hold m &m or life savers? How wide is the opening? Thank you.

How do you construct the tube holder? There isn't any directions and it would have been very helpful. It's very confusing.

What are the dimensions of the holder (length, width)?

One of the reviewers mentioned that the tubes do not have colored caps, but the picture shows them. Do they come with colored caps or plain ones?