Experience exclusive 4-Point Noise Masking System, Twin-Seal ear tips with 3x stronger Passive Noise Blocking, sound masking, and Smart Volume Control to prevent unwanted noise. Sleep A20 utilizes the combined efforts of soundcore’s Air Wing and 3D ergonomic design—wrapped in an ultra-soft material. Sleep mode boasts 14 hours of battery life on a single charge, Bluetooth mode offers 10 hours of playtime. Curate your sleep soundtrack with a stable Bluetooth 5.3 connection and a customizable white noise library to compose a perfect night's sleep. Using a MEMS sensor, Sleep A20 tracks sleeping positions and movement through the night. Coupled with a Real-Time Clock, enjoy precise sleep quality analysis.