Because the bottom of the mixing cup is the installation position of the battery, it can not enter the water when washing.

This product is specially designed to auto mixing coffee, milk, grain etc.What you need to do is press the button on the handle, it will stirring self mixing immediately.For both home and office use.

Product Description:
-Name:Automatic Stirring Cup
-Material:Food Grade Stainless Steel+Food Grade Plastic
-Inner Tank:High quality stainless steel
-Weight:308g
-Capacity:450ml
-Size:13.5*8.5cm
-Power: INNER BATTERY
-Battery:Two AAA Batteries(not included)
-Suitable for:Coffee/Milk/Grain/Oat

Features:
-Strong power, mixing evenly
-Easy and convenient operate
-Upgraded technology of leak-proof design
-Food grade material, eco-friendly and healthy
-Sealing mug cover, do not worry about liquid splashing
-High quality mute motor, you don't hear any noise when it work
-450ml big capacity, meet the general demand drinking of coffee or milk