Other features include a black rubber strap, scratch-resistant sapphire crystal, and water resistance to 30 meters (99 feet).

其他功能还包括一个黑色橡胶表带，防刮蓝宝石水晶，30米(99英尺)和耐水性。

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The quenching strap is a bit higher than unquenched area, it is stressed by its neighborhood. This is beneficial to the wear resistance of quenched strap.

淬硬层略有浮凸，并受到来自未淬火的基体的挤压力，这对于提高硬化带的接触疲劳强度是有利的。

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The Nao also has all of the features of its less advanced counterparts: water resistance, a comfortable and easy-to-adjust strap and a rechargeable Li-ion battery that, in a pinch, can be swapped out easily for two AAA batteries.

WSJ: The Petzl Nao: A Smarter Light | At Play