Please notice the stain. It could use a good cleaning but works perfectly! This Owlet Baby Monitor is the perfect tool for keeping an eye on your little one. With features like smartphone capability, oxygen level monitor, battery warning, and heart rate monitor, you can rest easy knowing your baby is safe and sound. The digital display makes it easy to read and the unit is portable for use on the go. The Owlet Dream Sock Model OBL 3.0 has a frequency of 2.4GHz (WiFi) and uses Bluetooth and Wi-Fi for smart home protocols. Made in China, this unit is sold as a single item and is ideal for babies weighing 12-30 lbs.