What makes this MOD perfect for the classroom? The 60-minute Time Timer MOD is a modern and portable time management tool perfect for teachers or students. It features a protective and removable, latex-free silicone cover, protective lens, has no loud ticking and offers an on/off alert for sound-sensitive environments. Also included is a free download of the popular Time Timer Desktop App, a classroom favorite for managing multiple groups and activities at once. The Time Timer MOD requires 1 AA/1.5V battery (not included).