Remove the safety cap just prior to ignition and light with a portfire. The electric fired squib is located at the other end of the unit. Uncoil the two wires. Extend the wires to a safe distance and ignite with a battery. Touch one wire to the positive and the other to the negative.
Ignition is immediate.
They can be angled 10 to 15 degrees away from spectators as illustrated in the picture at left. Or, they can be angled straight up and down if site and distance permits. The preferred angle is straight up and down. The units must be attached in a horizontal or vertical position to an upright wooden support. Nail the wheel to the wooden support.