ScienceWiz - DNA Double Helix Ladder Rungs AWARD WINNING ScienceWiz curriculum is designed to teach kids science in an intuitive and natural progression Create a simple model of the basic building block of life with this DNA model from award winning science experiment creator, Science Wiz Each pack features a double helix model with 20 ladder rungs in variously colored pieces for simple coordination Great for students learning about the basics of DNA and DNA structure Intended to be parts for use with science projects, science fairs, etc. and are provided with minimal to no operating instructions