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Osprey Antigravity 64 UNLTD Pack

Osprey Antigravity 64 UNLTD Pack
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Half a century of innovation has culminated in the industry-changing Osprey UNLTD Series designed by Founder Mike Pfotenhauer and Osprey’s innovation team.

A first-of-its-kind 3D Printed Fitscape™ Lumbar with Carbon DLS™ Technology offers supreme ventilation, fine-tuned support and anti-slip grip. The exclusive Men’s UNLTD AntiGravity 64 also features an innovative AutoLift System to automatically adjust harness length and a Fit-On-The-Fly® hipbelt for in-the-field, fine-tuned adjustment.

A clamshell design provides structure and enhanced compression while an anodized 7075 aluminum frame offers unmatched performance. Made from state-of-the-art fabrics and including a premium raincover and custom Airporter transit cover. Top lid converts to a fully functional lumbar pack.

Weight: 2.49kg / 5.5lbs
Carry Capacity: 25kg / 55lbs


Our unique design is supported by an internal frame that opens and closes like a clamshell, providing structure and easy access to the upper pack as well as an enhanced compression system.



A blend of aluminum and stainless steel is used to achieve a performance range that?s impossible to accomplish with a simpler solution. The spring steel works with the stiff aluminum frame to create the flex needed for a lively fit.



Adjustable hipbelt allows the fit to be fine-tuned in the field.



Removable top lid converts to a fully functional lumbar pack with hydration hose port and lumbar pad.

UNLTD AntiGravity suspension

Clamshell compression system

Convertible top lid lumbar pack with water resistant coated zippers

Dual panel access with laminated zip flaps

Twin front pockets

Super strong and break resistant YKK buckles

TPU cast anti-abrasion panels

Variable woven ski loops and tuck-away axe loops

Compression divider for sleeping bag storage

Removable sleeping pad straps

Large, versatile hipbelt pockets

Externally accessed reservoir sleeve

Injection-molded hydration hose routers

Stow-On-The-Go trekking pole attachment

High tenacity nylon ripstop raincover located in base zippered pocket

Custom Airporter travel cover with lockable zippers


No need to adjust and readjust load lifters while hiking. AutoLift automatically engages the upper frame of the pack, keeping the load close to back, stable and in proper balance.

Works directly with CamLock Torso Adjustment System to quickly set the optimal position for shoulder straps.


Blends multiple components perfectly to create optimal performance.

The main tubular anodized 7075 aluminum alloy frame element provides outstanding vertical stiffness to resist collapse under load and maintain tension on backpanel mesh.

Two horizontal stainless steel wires at the bottom of the frame deliver spring tension to the hipbelt area, controlling flex and fit.

A pair of custom-molded hubs join the tubular aluminum and stainless steel wire elements together at the lower corners of the backpanel, allowing each material to offer its unique performance advantage independently.

Additionally, the injection-molded hubs are exposed through the fabric at the bottom of the pack, providing a buffer and preventing wear when it is set on the ground?the hard nylon material can tolerate a lot of abuse without any issues.


Micro-adjustable self-locking cams allow torso length to be quickly and easily adjusted to a perfect fit while the pack is worn.

Simply lift up on the buckle lever to release the webbing and adjust the shoulder harness upward.


Advanced 3D printing technology delivers a uniquely supportive lumbar pad.

Flex and shape are tuned to support load evenly and reduce pressure points.

Open structure ventilates and reduces heat buildup.

Polymer compound grips securely to promote load transfer and eliminate slippage.


Osprey UNLTD™ Series

Designed without restrictions by Founder Mike Pfotenhauer and Osprey’s innovation team, the industry-changing Osprey UNLTD™ Series looks beyond traditional manufacturing technologies to bring you the ultimate backpacking experience. New processes and materials are reflected throughout the Series, but perhaps most evident in the first 3D printed lumbar in the industry. Combined with our award-winning suspension, an uncompromising feature set and state-of-the-art materials, the future of pack design is here. Welcome to Osprey UNLTD™.

Part Numbers

Option MPN Store SKU
Small/Medium UNLTDM6463-BLUE-S/M PAC534826442
Large/X-Large UNLTDM6463-BLUE-L/XL PAC548889392