It does 3,4,6 and 12 lead ECG.

Why doesn't it do 9 or 10 lead ECG?

There is a nurse's textbook that says standard cardiac measurements use 9 or
10 lead ECG. Nurses that use that textbook go on to work in world famous
cardiac hospitals.

I guess Burdick doesn't sell that unit to world famous cardiac hospitals or
it is just kept secret from nurses.

RB can come out from hiding behind that nurse's skirt now. He's been busted
wide open!