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Gregory Inertia 25 3D Hydro Pack · Shadow Black

Gregory Inertia 25 3D Hydro Pack · Shadow Black

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Product details
Official manufacturer description

The Inertia 20 keeps a low profile and clean exterior that won’t slow you down as you tear up the trail. Bring a rain shell, hat, and gloves for changing conditions in the fall and spring, but leave your water bottle behind and fill up the included Gregory 3D Hydro reservoir.


  • Includes 3D Hydro quick drying, soft molded reservoir (3 Liter) with integrated drying hanger.
  • Dedicated zippered hydration sleeve with SpeedClip hydration hangar for a one-handed, snap-and-go connection.
  • Die-cut shoulder harness with magnetic sternum buckle and hose clip for the Drylock bite valve.
  • Breathable die-cut backpanel webbing hipbelt.
  • Sunglass QuickStow system on shoulder harness for quick, secure and scratch-free access to your shades.
  • Top zippered pocket with key clip and front zippered pocket with soft touch liner to protect valuable items.
  • Front and dual side stretch mesh pockets for quick storage.
  • Trekking pole/tool attachment with bungee closure system.
  • Custom comfort-grip molded zipper pulls and molded webbing keepers for strap management.
Shadow Black
Backpack Material(s)
210-denier Honeycomb CryptoRip nylon
Intended use
Daypacks, Hydration packs, Hiking
1.58 lb
Backpack capacity (L)
25 L
Reservoir compatible
One Size
Age Group
Frame type
Backpack dimensions
20.1 x 11.5 x 8.5 in.
Backpack Hip Belt
Hipbelt Pockets
Gregory Inertia 25 3D Hydro Pack · Shadow Black
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Jenn L.
Jenn L.
Verified camping & hiking expert
Reviewed Jul 13, 2022

A bigger day pack for when you need to carry extra layers or extra gear. Has an external mesh pocket for easy access to certain items. Gregory is known for making durable, and comfortable equipment.