The blue LED back-light is always turns On. Available in 12 and 24 hour versions. 3 keys operation. External powered with 3.3VDC. Normally the alarm time is one minutes, and configured in 4 individual output poles for each alarm normally.
LCD clock module, 12 or 24 hour version, 4 daily alarms, with blue color LED backlite. Backlite in amber, yellow, green, and white colors are available too. 12 or 24 hour versions are available. 2 pieces of AAA (UM4) battery holder is mounted on the back for testing purpose only.