Ignition module is also known as the switching unit. It is used to regulate the current and dwell angle for transistor ignition systems using a hall sensor or inductive sensor. It provides for reliable spark distribution in ignition systems with rotary high voltage distribution. It used for switching power to the coil, usually in response to signals generated by a mechanical distributor. It can also be driven by an electronic ignition advance/retard unit or engine management electronic control unit.

Ignition Wrenches are constructed of drop forged alloy steel that is heat-treated, oil-quenched and tempered for uniform hardness and maximum strength. Its features are nickel-chrome plated to resist rust and corrosion & to simplify cleaning, chamfered edges to prevent rounding and 5-degree offset handle for better knuckle clearance & an open-ended wrench about 3 inches (75mm) long. It has two jaw openings set at different angles to the handles.