Sharp Mobilon HC-4000 Operation Manual page 11

Hard, sharp objects can scratch your unit, so ensure it is closed and/or
protected when carried with other objects.
Do not use solvents to clean your unit. Use only a soft dry cloth.
Do not carry your unit in your back pocket as it may break when you sit
down. The display is made of glass and is particularly fragile.
Since this product is not waterproof, do not use it or store it where
fluids, for example water, can splash onto it. Raindrops, water spray,
juice, coffee, steam, perspiration, etc. may also cause malfunction.
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