Tender For supply of bearing and machine noise kit (electronic stethoscope). technical details: - frequency range:30 hz - 15 khz, operating temperature: -10 to +45 degrees c, output volume: adjustable in 15 levels, display: lcd (black &white), sound volume: up & down, battery low signal: yes, case contents: instrument, headset, probe: 70 mm and 300 mm, 2 x aa alkaline battery, instructions manual. make/model: skf- tkst11 or equivalent. [ warranty period: 30 months after the date of delivery ]