E21-TVS modely mají 2 řady tlačítek po 6 pro volbu vstupů, Cut a Auto tlačítka a 2 uživatelská tlačítka.

• 16 red, green or ambient broadcast quality buttons
• Transparent button caps for custom labels
• Slider for transitions
• 2x8 channel BlackMagic Design compatible DB-25 connector for Tally output and GPI (optional)
• Power over Ethernet for the E21-TVSS. Your network switcher needs to be PoE compatible (optional)
• All buttons fully programmable
• Web configuration interface for settings (Optional: See "TVSL" variant)
• Completely self contained unit with Arduino Ethernet or Arduino Mega inside
• Durable enclosure with black or blue anodized aluminum plates
• Compatible with all BMDs video switchers: Television Studio, 1 M/E Production Switcher, 2 M/E Production Switcher, Production Studio 4K. 1 M/E Production Studio 4K & 2 M/E Production Studio 4K
• Japanese quality buttons with almost infinite lifetime
• 100% Creative Commons/Open Source design (CC-by-sa or GNU/GPL)