NOTE: See my review of the updated-for-2024 versions of the Deuter Aircontact Ultra 50+5 and 45+5 SL backpacks.
Ultralight Backpack
Deuter Aircontact Ultra 50+5
$250, 55L/3,356 c.i., 2 lbs. 11 oz./1.2kg
Deuter Aircontact Ultra 45+5 SL
$250, 50L/3,051 c.i., 2 lbs. 11 oz./1219g
One adjustable size in both models
Aircontact Ultra 50+5: backcountry.com
Aircontact Ultra 45+5: backcountry.com
Many mid-size, lightweight and ultralight backpacking packs share more similarities than differences—because the design details they share have proven popular and work. Still, Deuter’s Aircontact Ultra 50+5 and 45+5 SL distinguish themselves from some competitors for their adjustable, comfortable fit and smart design details that make a difference in your experience carrying it, as I found using the Aircontact Ultra 45+5 SL on a five-day, late-summer backpacking trip in the Wind River Range and a three-day hike on the 22-mile Boulder Mail Trail-Death Hollow Loop in the Grand Staircase-Escalante National Monument in early October.