This is a Plus Style sleep checker. I used it once, but it's in good condition since I haven't used it since. It includes the AC adapter and the main unit. The box and instruction manual are not included. The AC adapter connects to the main unit via micro USB. It can measure sleep score, sleep rhythm, sleep duration, and deep sleep amount. You can also check your heart rate, breathing rate, and number of times you turn over during sleep in a time series. Model number: PS-SSL-W01 JAN code: 4580539423380 External dimensions: Main unit: approx. 105mm x 88mm x 17.6mm Belt: approx. 800mm x 65mm x 2mm Weight: approx. 130g (main unit only) Weight: approx. 130g (main unit only) Power consumption: 5W AC/DC adapter specifications: Input: 100-240V~50/60HZ 0.25A Max Output: 5V / 1A Cable length: 2 meters, with switch Wireless method: IEEE 802.11 b/g/n (2.4GHz) Measurement items: On/off bed, heart rate, breathing rate, number of times turning over Analysis items: Sleep duration (sleep onset time, sleep end time), sleep rhythm, deep sleep amount, sleep score Main unit material: PC+ABS, PC+TPU You can measure your sleep data simply by placing the 2mm-thick belt under your sheets while you sleep. It can also be used with futons. Since it is not attached directly to your body, it does not interfere with your sleep. It can be used by those who are not fond of wearable sleep trackers. It is recommended to place it on a futon or mattress with a thickness of 8-24cm.