Features Option A is great for direct drive systems as it will allow for safe electronic control of reversing. Option A is essential for maximizing the benefits of a dual motor system. When connected to the appropriate contactors with microswitches an option A Hairball allows for quick and arc-less series/parallel switching. Launch in the series configuration for maximum torque and switch to parallel for higher top end. A Hairball equipped with option A allows the user to attach a separate switch to activate the series-to-parallel shift function or the Hairball itself can autoshift at the optimum time.

-P: The Hall Effect Pedal input option. This option enables the Hairball to use the HEPA throttle pedal which is sold separately. The Hairball with the -P option installed must use a HEPA pedal for input, it can no longer be used with a normal pot box. Please see the HEPA pedal listing for important fitting information. This option is available on the base Hairball or in combination with the -A or -S.

-S: The Sparrow option was made for use in Sparrows but also has other applications. This option adds two contactor drivers to the standard model for forward/reverse switching of one motor. Unlike the -A option, the Sparrow option has been configured so that it can use reversing contactors that do not have built in microswitches for sensing contact position. This is good for vehicles like the Sparrow which are configured to use the Kilovac EV200 type contactors for reversing therefore it is better to use the -A option when possible. The -S option also has default settings that are reasonable for a Sparrow. Settings can be changed after setting the defaults. This can be combined with a -P option