S30 Kids Smartphone Watch Precise Location Positioning

Watchband
The watchband is a general term for the effective part of a watch to fix the wrist. There are many kinds of watchband materials. Cowhide is the most common one, while crocodile skin is the most precious one. crocodile skin watchband is also known as "platinum" in leather watchband
Precious metal material
⑴ Platinum is a rare and expensive natural white metal, which is one of the rarest precious metals for jewelry in the world. Its annual supply is only 5% of , with almost twice the strength of , and 30 times rarer than . Platinum is white, natural and , with a purity of more than 90%. It is natural and will not fade when worn frequently. Pt900 represents platinum jewelry with a purity of 90%, and Pt950 represents platinum jewelry with a purity of 95%.
2) K K refers to the alloy of mixed with other metals. Because its English name is Karat , it is called K for short. Precious metal: is , but is too soft to make watches. It must be mixed with other metals to strengthen the hardness. Generally, silver, copper and palladium are the main metals. However, no matter what kind of metal is mixed, accounts for 75%. With the proportion of , silver and copper, five different colors of materials can be produced. The copper content is represented by N, for example, the highest copper content of red is represented by 5N, while white is correctly described as white .
3) Semi
The stainless steel and 18K materials are used together to present a unique two-color aesthetic feeling.
4) The coated case is made of stainless steel, wrapped with a layer of alloy, and rolled into a whole by mechanical rolling. Its thickness is measured in micrometers, and 1 micrometer is equal to 1/1000 mm. Up to 10 to 15 microns thick, generally only 2 to 3 microns thick.
5) Electroplating ( plating, thanks to brother wiiasa, electroplating should be placed in the properties of precious metals, which will be explained in the hearing below) is a common decorative method for watch cases in modern watches. The electroplating technology rose in the 1970s. Because the electroplating is uniform and solid, lower than the coating cost, and is not easy to fall off, and there is no possibility of discoloration and corrosion of forged yellow shells, the two will soon be eliminated from the market.
6) Silver "In terms of purity of silver, 925 is not the highest purity of silver! You can see that the domestic instant silver prices are 99.99%, 99.95% and 99.90%, respectively. These three kinds of transaction purity are too soft to be used as jewelry. Generally, 92.5% is the most suitable for jewelry (hardness, ductility, etc.), so 925 can also be called silver. But it is not really silver." Silver is an ancient precious metal, which is the most used material for pocket watches in the 18th century and before. 925 represents the purity of silver, which is the highest purity of silver (not the highest purity, common ones are 925 -- suitable for jewelry, 975 -- suitable for tableware, 990, and more -- Kaiting Note). Silver is an active metal, which is easy to react with sulfur in the air, forming a black oxide layer and blackening the silverware. Nowadays, it is far inferior to in watch application because it is easy to lose luster due to water, moisture and other reasons.


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