Air velocity measurements as low as 40ft/min Telescoping probe is ideal for use in ducts and ventilating systems, extends up to 3ft (940mm) long Measures air volume in CFM (ft3/min) and CMM (m3/min) plus Temperature simultaneously Air Flow displayed in 2 modes as an instantaneous value or up to 20 point average Record/Recall MIN and MAX readings Super large 1.4 (99,999 count) LCD display Data Hold plus Auto Power Off Built-in RS-232 PC interface with optional Data Acquisition software and cable > Each Unit Includes Telescoping probe with 5.5ft (167.6cm) cable Four AA batteries