The calibration matched my reference unit. 

Shipping is $7

Tested Analog ADC SLM-3 Sound Level Meter Calibration is good 

MY REFERENCE #slm3

30 DAY WARRANTY

MANUFACTURER: ADC

MODEL: SLM-3

FUNCTIONAL CONDITION: ON A SCALE OF POOR/FAIR/GOOD/EXCELLENT ITS IN THE EXCELENT CATEGORY.

COSMETIC CONDITION: ON A SCALE OF POOR/FAIR/GOOD/EXCELLENT ITS IN THE GOOD CATEGORY.  SOME  MARKS AND SOME SCRATCHES. 

REGARDS,

PAUL