This is a 122 kit for Hammond consoles. It is “plug and play” - meaning no soldering or hooking up wires. It provides a 6-pin Leslie 122 type output (also works for 21H, 22H, and 31H type Leslies). This type of connection is also referred to as a "6H" output.
The kit plugs into the organ’s stock Tone Cabinet output. This will be a 5-pin plug for all Hammonds built from 1950 onwards, or a 6-pin plug for all Hammonds built 1949 and earlier.  Count the number of pins on your organ's tone cabinet output jack, and select the matching "Organ Connection" option from the pull-down list when ordering. The 6-pin option will carry B+ (high voltage DC) from the Leslie amplifier to the organ's preamp.
Speed control switch plugs into the kit via 1/4” jack.
Can be ordered without a switch (provide your own), with a footswitch, halfmoon switch, 2-button footswitch for 3-speed EIS operation, or 3-position halfmoon for 3-speed EIS operation. (3-speed operation requires a EIS type relay is installed in the Leslie amplifier).
 
As a bonus, a line level 1/4” output is also installed in the box, allowing you to plug the organ into any amplifier/bass amp/PA system etc. This can be used simultaneously with the 122 output.