DIY Paper Telescopic Periscope Inventions Manual Physics Experiment Assembly Models Pupils Technology Small Production Material Kits Specifications: Material: Paper Size: 260*40*40mm/10.24*1.57*1.57" Recommended age: Over 3 years of age Experimental principle: The paper periscope uses two mirrors to make light reflect through two reflections, so that the underwater world can be seen. Small model non professional periscope, please do not compare with professional periscope. Experimental steps: 1. Fold the periscope, fold the paper periscope along the edge line of the paper, and attach the adhesive tape to the joint. 2. Tear off the two lens films and fix them on the top and bottom of the periscope respectively. The two ends are connected and the long end is inserted into the short end. Be careful: Contained with small accessories and sharp objects, Children should be accompanied by adults. Please take good care of children and avoid swallowing. Because the display pixels are different, there may be a bit of chromatic aberration. Due to different measurement methods, there may be errors in allowing 1-3cm. Package include: 1 Bag X Periscope Material Kits