... li-ion battery Evaluation length : 5 cut-off SEPARATE PROBE Ra, Rz, Rq, Rt SURFACE ROUGHNESS TESTER SRT-6400 Specifications:Display ... 4 digits, 10 mm LCD, with blue backlightParameters: Ra, Rz, Rq, RtMeasuring Range Ra, Rq: 0.005-16.00um/0.020-629 ... Extension Rod3. Groove stylus4. Curvature Probe5. Measurement Stand6. Bluetooth interface Ra SRT6400 surface roughness tester,roughness measure instrument