With the Koch CFS-5, you give the Koch FS5 footswitch, used for the Twintone II amps, among others, 5 metres of extra cable length.
Via the DJ-1 adapter, you connect a regular MIDI switcher to a Koch amp, and then use it to control functions such as channel selection and rhythm/solo. Only requirement is that the amp has a 7-pin DIN input.
The Koch FS2-SN is a 2-button footswitch intended for use with the Koch Supernova amplifier tops.
The FS2-ST footswitch is specially designed for Studiotone amps. With its two switches, you can alternate between overdrive and clean and it is possible to give the distorted channel a little extra.
The Koch FS6-SN is the 6-button footswitch for the Koch Supernova amplifier tops.