Eisco - Mole Set with 4 Metal Bars Representing 1 Mole of Copper, Iron, Zinc, and Aluminum for Chemistry Education

The quality of these is great, and they come with a sturdy little plastic box. It's great that they are not labelled with what they are, so it can be a sort of mystery. One easy solution without doing any measurements is to use a magnet, and then the others are obvious.This set is not ideal for doing density by weight-in-the-hand, since each piece is a different size.

The weights are very close to the reference table accepted masses.