Get Microsoft Natural Ergonomic Keyboard 4000 Function Keys US. It includes hot keys, multimedia keys, a palm rest and more. I'm trying to get the special keys on my natural ergonomic keyboard 4000 working under os x el capitan.
The newest models are the sculpt ergonomic keyboard (2013) the surface ergonomic keyboard (2016).
The microsoft natural keyboard doesn't have an eject key. The oldest is the microsoft natural keyboard, released in 1994, the company's first computer keyboard. Rather than being raked toward you, the keys slope down as you go. I would had never expected a special key blocking the other function keys.