What does the settings A1 thru A5 mean on my MultiServe?

The settings A1 through A5 are your altitude choices to program your unit for optimal performance based on the altitude of where you live.

Altitude (m/ft)	0 – 499 / 0 – 1637	500 – 999 / 1638 – 3278	1000 – 1499 / 3279 – 4918	1500 – 1999 / 4919 – 6558	2000 > / 6559 >
Parameter	A 1	A 2	A 3	A 4	A 5