Tree Measurement, Skill Builder CardsCreate a strong foundation of knowledge in the classroom before taking students to the outdoor lab with our Skill Builder cards. Our cards are great for introducing the content, using as an evaluation, or even as an indoor lab if weather or time keeps you from venturing outside. The set includes 40 diameter cards and 40 height cards that are all printed in color and laminated. These cards make it every easy to teach clinometer and diameter tape use