Invisible Infrared LED Password Display - Escape Room Prop

The LED board will display the password, but is invisible without the infrared ray. Use an ordinary cellphone's photograph function to find it.

Please prepare the ordinary cellphone yourself.

Packing list:
1 LED display board 
1 12v power supply

Features:
1. User can change the display password via the S1 key on the board.
2. The display number can be 1-100.
3. Set whatever password you like, for example 54321.