The plywood box coil base is a 30" cube on castors. The rotary spark gap is on the left and the primary capacitors are on the right. There two 0.22mfd at 30kV capacitors in series. The synchronous Rotary Spark Gap spins at 3600 RPM. The center, spinning disk is 12" in diameter at the electrodes. The outer "stationary" disks can be rotated through 120 Deg. for phase adjustment. Each "stationary" disk rotates independently for dwell adjustment. These adjustments are motorized and remote controlled and can be made during operation. There are 4 gaps, each about .050 inch. Best sparks are with 45 Deg. phase offset for 4 sparks per line cycle. (Thanks to Bill Wysock for cutting the motor armature for synchronous operation.) The black straps with the plywood adjustment blocks limit the travel of the coil base when it is tipped over for inclined operation.