This is a tool for personal sleep measurement. It is used in conjunction with an app installed separately on your smartphone. It is a brand new, unused item as I recently purchased it. I opened it for the purpose of taking photos. ※Product Description [From the manufacturer below] Measure. Improve. Accumulate. With this one device, your sleep evolves. Based on sleep research, we have incorporated a proprietary algorithm and applied technology used in sleep research. It reveals your sleep stages (depth of sleep), sleeping position, snoring/environmental sounds, and bed temperature (temperature inside the futon), which were not visible with conventional sleep measurement devices. ■Device ・Main unit 7g, clip 11g ・Materials ・Main unit: ABS resin, PC (polycarbonate) ・Clip: Silicone, stainless steel ・Button battery: CR2032 ・Bluetooth connection ・Color: Blue Thank you for viewing.