TACHOMETER The Extech Combination Photo/Contact Tachometer features a unique display where characters reverse direction depending on measurement mode selected. The meter combines both contact and non-contact models to provide wire RPM measurements. Specifications:  Photo mode range: 5 to 99,999rpm Contact mode range: 0.5 to 20,000rpm Resolution: 0.1rpm (< 1,000 rpm); 1rpm (>1000rpm) Accuracy: 0.05% rdg +1 digit Photo mode sampling time: 1 sec> 60rpm  Contact mode sampling time: 1 sec> 6rpm Contact mode surface speed: 0.2 to 6560ft/min, 0.05 to 1999.9m/min Power: 4 AA batteries Dimensions: 8.5 x 2.6 x 1.5 (215 x 65 x 38 mm) Weight: 10.6 oz (300 g) Warranty: 1 year