|Swoffer Model 2100 Current Velocity Meter / Current Meter. Read stream velocity directly from 0.1 to 25 feet (.03 to 7.5 meters) per second. Data displayed in either feet or meters per second. Three selectable pre-set display update times. 90-second maximum. Powered by a single standard 9V battery. Uses the efficient, propeller-driven Photo-Fiber-Optic sensor pioneered by Swoffer. Precision quartz crystal controlled electronics provides accurate, precise data in all flow conditions. Please call 1-614-846-1900 for details.