This product has been discontinued. Replaced by 407790A - Real Time Octave Band Analyzer.
Extech 407790

Extech 407790: Real Time Octave Band Analyzer

Type 2 integrating sound level meter with Octave and 1/3 Octave Band real time display

Extech’s Type 2 Integrating Sound Level Meter with Octave and 1/3 Octave Band Real Time.