1. Material is of aluminum alloy and glass;
2. Special design of fluorescent light, you can read data on it in dark environment after absorbing enough sunshine；
3. Waterproof and shake-proof, suitable for motoring, boating, camping, mountaineering, exploring, hunting and other outdoor activities;
aluminium alloy and glass
With inch and cm ruler
popularization of science
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The compass opened the world market.
The application of compass in navigation greatly promotes the discovery of geography and maritime trade. The invention of the compass originated from the study of how to orientate in ancient China, and also showed that the ancients attached great importance to how to orientate. Therefore, the compass was praised as one of the four great inventions in ancient China. Ancient Chinese used the compass in military and navigational activities, but also used in public opinion, and later spread to Europe, in the European navigation activities and geographical discoveries, played an irreplaceable important role. Compass is also the most important single invention in the invention of navigational technology.