Duluth Lab Student Set - molecular Chemistry model set with all the pieces listed, + 4 extra carbons. The sticker on the case is peeling a bit, but the rest of the box and the contents are all in great, pre-used condition. Like adult tinker toys that help you learn chemistry. Used in college level organic and molecular chemistry classes, but could make a great STEM toy for older kids. This item qualifies for the 3 for $25 sale.