Bomb prop in medium/small case with clock mounted on the outsideand keypad- When correct code is put into keypad (reporgrammable to 2-19 digits)  then it triggers mag lock to open case. When in the case is there is 5 colored buttons, (reporgrammable to 2-19 code) and when correct code is input then the DISARMED light comes on inside.
Option to have 5 buttons on outside of box with timer and keypad inside with disarmed light
Comes with mag lock and power supply. Plug and play.
 
Option to add sound with small speaker inside or speaker with wire running outside of box. SD card programmable sound. Sound when they disarm is you want and sound if they blow up and do not disarm.
 
See video here