The max count days is 1000 days(999 days 23 hours 59 minutes 60 seconds) Excellent brightness and visibility for indoor activities Easy mount to wall can countdown and count up 12VDC work voltage, low power consumption This clock is designed for long time countdown. It consists of days hours minutes seconds. Days will run by the time behind it, which is hours minutes seconds runs a day, which is 23 hours 59 minutes 59 seconds, days will change once. You can define days countdown and hours minutes seconds countdown or days count up and hours minutes seconds count up. Also you can program days countdown hours minutes seconds part work as a real time clock. All these settings can be easily done The clock dimension is about 110x16x4cm and weight is around 3.4kgs. You can also easily mount to wall with our brackets.