Owlet Baby Monitor 1st series. Includes 5 socks. Two of them are replacements ordered online that look brand new. No obvious stains on them. Note that series 1 and 2 no longer use the app. It still works and will go off from the owlet base if there is a low battery, off of baby’s foot, or if the baby’s heart rate or oxygen is off. The instruction booklet is not included.