Five-hundred | meter

Meters
unit.meas. abbr.	M
meter
abbr.	m
abbr. oil	m; mtr
abbr. plast.	metre
IT abbr.	m
metrol.	A device intended to make a measurement, alone or in conjunction with other equipment

| Aperture

aperture
abbr. oil	ap

| Spherical | radio Telescope

Radio Telescope
NASA abbr.	RT