The EFA (Electronic Focusing Accessory) control box can be mounted to the back plate of any PlaneWave telescope OTA (12.5 through 24 inches). The EFA Kit reads the primary mirror and ambient temperature sensors.The EFA controls the fan systems that are built into each telescope.

A Hand Controller is provided to control an optional Focuser or Rotator when standing at the eyepiece. The EFA kit comes with PlaneWave Interface (PWI4), a software package that controls all EFA functions from a PC. Cables and adapters are provided to attach the EFA kit to a PC. The EFA kit is ASCOM compatible.