The MXR-D is the only digital flowmeter with both a digital display and calibrated glass indicator tubes for accurate real flow display.

Combining Porter precision and technology- the MXR-D "is the best of both worlds" combining digital technology as well as the precision of Porter glass indicator tubes. N20 and O2 indicator tubes allow for accurate visualization of real-time flows as well as ensuring no disruption of N20/O2 flows in the event of a power disruption during the procedure. Brightly lit digital display enables readings to clearly be seen from across the room. 

The MXR-D features ergonomic total-flow and percentage adjustment knobs, advanced needle valve technology, visual and audible alarms, on/off switch, and oxygen flush button. The MXR-D is also the only digital flowmeter with an oxygen quick-connect built into the flowmeter for fast connection of emergency oxygen equipment. Easily mounted into the cabinets, walls or pediatric benches.

http://www.porterinstrument.com