According to Ring, the sensor is able to detect glass breaking or being cracked and differentiate between similar noises, preventing false alarms. 
You’ll need to have a Ring Alarm or Alarm Pro in order to add the Glass Break Sensor to your home’s security setup. Each sensor has a range of up to 25 feet and can be mounted to your wall, ceiling or placed on a shelf near a window or glass door.  
When broken glass is detected, the sensor will send an alert to the Ring mobile app and if your alarm is armed, notify the Ring Alarm monitoring service. The Ring Alarm Glass Break Sensor will be available to order starting today, with orders shipping on Feb 16. Each sensor costs $39.99.
Ring has two different alarm offerings. The standard Ring Alarm or the Ring Alarm Pro doubles as an Eero Wi-Fi system for your home, providing a backup internet connection when your home loses its internet connection. Naturally, the alarm product offerings directly integrate with Ring’s camera lineup.