Amazon.com: BOSS EV-5 Expression Guitar Pedal & M-Audio SP 2 - Universal Sustain Pedal with Piano Style Action For MIDI Keyboards, Digital Pianos & More : Everything Else
Boss FS-6 – Thomann UK
Found Vintage Boss Foot Pedals : r/pedals
Guitar Pedal X - GPX Blog - Pedal Design 101 - The Boss Colour Chart and 40 Shades of Tone!