I've used this for about two months, but it didn't suit me, so I'm selling it. Price negotiations are not possible. [Quoted from HP] Model number: CIO-EYEMASK01 Battery capacity: 600mAh Weight: Approximately 100g (battery: approximately 20g) Input: DC5V USB-C Output: 5V=0.8A Size: Approximately 48 x 30 x 10 mm Operating time: Approximately 20 minutes Operating temperature: Low: 37℃, Medium: 40℃, High: 45℃ *Inner surface temperature.