Using the Korg padKontrol as a sustain pedal (or other functions)
Korg PS3 Momentary Footswitch - Perfect Circuit
PS-1 - PEDAL SWITCH | KORG (USA)
Korg Sustain Pedal | Reverb
Amazon.com: Sustain Pedal for Keyboard - Sovvid Piano Foot Pedal with Polarity Switch for All Brands Electronic Keyboards, MIDI Keyboards, Digital Pianos, Yamaha, Casio, Roland, Korg, Behringer, Moog and More : Musical
Amazon.com: KORG PS-1 Single Momentary Pedal Footswitch for MIDI Keyboard : Musical Instruments
Korg DS-1H Piano-style Sustain Pedal with Half-damper Control | Sweetwater