LV (Low-Voltage) Version:

• 16 Flexible I/O (Digital Input, Digital Output, or Analog Input)
• Up to 2 Timers (Pulse Timing, PWM Output, Quadrature Input, ...)
• Up to 2 Counters (32-Bits Each)
• 4 Additional Digital I/O
• Up to 16 12-bit Analog Inputs (0-2.4 V or 0-3.6 V, SE or Diff.)
• 2 Analog Outputs (10-Bit, 0-5 volts)
• Supports SPI, I2C, and Asynchronous Serial Protocols (Master Only)
• Supports Software or Hardware Timed Acquisition
• Maximum Input Stream Rate of 2.5-50 kHz (Depending on Resolution)
• Capable of Command/Response Times Less Than 1 Millisecond
• Built-In Screw Terminals for Some Signals
• OEM Version Available
• USB 2.0/1.1 Full Speed Interface
• Powered by USB Cable
• Drivers Available for Windows, Linux, Mac and Pocket PC
• Examples Available for C/C++, VB, LabVIEW, Java, and More
• Includes USB Cable and Screwdriver
• Free Firmware Upgrades
• Money Back Guarantee
• Enclosure Size Approximately 3" x 4.5" x 1.2" (75mm x 115mm x 30mm)
• Rated for Industrial Temperature Range (-40 to +85 Degrees C)

HV (High-Voltage) Version:

Same features as the LV version except:

• First 4 Flexible I/O are Changed to Dedicated HV Analog Inputs.
• 4 HV Inputs have ±10 Volt or -10/+20 Volt Range.
• 12 LV Inputs (Flexible I/O) Still Available, for 16 Total Analog Inputs.

For more technical specifications look at the U3's datasheet.