Amazon has the Ring Alarm Glass Break Sensor for $16 with free shipping on $35+ or with Prime. Detects the sound of glass breaking up to 25 feet. Also on sale: 

• Ring Alarm Keypad (2nd Gen) for $20
• Ring Alarm Panic Button (2nd Gen) for $12
• Ring Alarm Flood and Freeze Sensor for $16
• Ring Alarm Contact Sensor (2nd Gen) for $11
• Ring Alarm Motion Detector for $14