100% brand new and high quality. Incredible physical laboratory equipment aid tool, or as a decoration in your lab,making physical experiment learning more efficient. This instrument is used to explain the statistical instrument of the statistical regularity of the velocity distribution of gas molecules. The instrument is composed of a plate, an array of nails, a V-shaped groove, a plug-in plate, a slot and the like. Good for school teaching tool, learning display, and collectibles, also will be a great addition to your lab supplies.