For those bomb defusal games, then you now have something to use without making one for your own use... "Our airsoft 'time bombs' are programmable electronic timer devices that do not explode (unless you put explosive charges in them). They are timers the purpose of which is to emulate time bombs that count down and can be defused. They will not throw BB's or other kinds of fragments. Read the airsoft time bomb FAQ.

Belonging to the Pocket Series, a new, cheap and simple model will soon be available called AST-CS1. 'CS' stands for Counter Strike as this model will work exactly the same way as the bomb does in the game. Naturally, it will come with a defusing kit, which decreases defusing time. Time of activating, countdown and defusing will be the same as in the game."