These rugged industrial LED stroboscopes provide an extremely bright, uniform light output for performing stop motion diagnostic inspection and RPM measurements. The twelve LED light source design provides an extremely efficient light source resulting in continuous cool operations leading to a long battery life. With a wide operating range of 30 to 500, 000 flashes per minute these units cover most applications. The bbl basic 6231-011 is designed for simple stop motion inspection and RPM measurement applications. The DBL Deluxe 6231-011 includes all standard features of the bbl basic with the addition of internal phase shifting, memory for up to five preset Flash rates, n.I.S.T. Calibration certificate, and Tachometer mode for speed measurements up to 500, 000 RPM using optional remote sensors or TTL pulse input/output. The PBS Phaser advanced 6231-011 has all the features of the DBL with the addition of external phase delay, time delay, virtual RPM mode, and a power supply/recharger that allows for 24/7 continuous operation. Whats included: 115/230 VAC, 50/60 Hz recharger with us, UK, AUS, and Euro adapter plugs, plastic latching carrying case, and calibration document supplied by the supplier. Adjustable brightness control in a lightweight industrial design twelve button keypad makes entering Flash rates quick and easy (DBL, PBL models). energy efficient with long battery life - up to 10 hours.