The headphone hole is set for inserting your headphone device, so that you can feel the most real sex experience when you close your eyes while your knees are shaking.

Only the inner sleeve is waterproof. Remove from mug and wash with soap and running water, very easy and convenient. Please note that water in the cup can damage the device.

USB charging allows for longer usage and easier charging. Be careful not to plug all the charging pinholes in! Otherwise, it will not charge!