MSR DromLite Water Reservoir, 4-Liter, Collapsible Hydration Bladder with 3-in-1 Cap, Lightweight RF-Welded

The MSR DromLite 4-Liter Bag is a rugged, ultra-packable water reservoir that stores four liters and collapses down to the size of its cap for minimal bulk.

Designed for backpacking, bikepacking, and extended outdoor trips, the DromLite combines a light overall weight with a tough laminated film and RF-welded seams for dependable field performance. An improved BPA-free food-grade lining keeps water tasting clean while tolerating cold conditions, and the included MSR 3-in-1 cap makes filling, pouring, and drinking straightforward. The 4L model balances capacity and packability, folding flat when empty to save space inside a pack or drybag.

How does the DromLite 4L save space in a pack?

The reservoir is engineered to collapse completely once emptied, reducing its volume to roughly the size of the cap. That makes it easy to stash in a corner of your pack or inside a compression sack, freeing room for other gear.

• Collapses flat to the size of the cap for compact storage
• Lightweight 5.1 oz (approx.) minimizes carried weight
• Flexible film conforms to pack shape to eliminate dead space

What makes the materials durable and safe for outdoor use?

The DromLite uses a laminated resilient film and RF-welded seams that resist punctures and leaks while remaining lightweight. Its inner lining is a BPA-free food-grade material that preserves water taste and tolerates freezing conditions better than many standard reservoirs.

• Tough laminated exterior for abrasion resistance on trails
• RF-welded seams reduce leak risk compared with glued joins
• Improved BPA-free lining for neutral tasting water and cold resistance

How do I fill, pour, and drink from the DromLite?

The MSR 3-in-1 cap included with the reservoir provides three convenient functions: wide-mouth filling, controlled pouring, and a drink-through option. The cap design simplifies refilling from streams or water pumps and speeds camp tasks like cooking and washing.

• Wide opening for fast filling and easy cleaning
• Pour spout for transferring water into pots or bottles
• Drink-through capability compatible with hydration kits and hoses

Can the DromLite handle freezing temperatures and accessories?

The laminated construction and inner lining make the reservoir more tolerant of cold than many soft bladders, and it works with MSR Shower and Hydration Kits to expand functionality. While not indestructible in extreme freeze-thaw cycles, it stands up to typical alpine and winter conditions better than thin-film alternatives.

• Rugged 1,000-denier exterior resists cold-related damage
• Compatible with MSR Shower and Hydration Kits for multiuse setups
• Built to perform across a range of temperatures for seasonal use

Who this is for: The MSR DromLite 4L is aimed at hikers, backpackers, and bikepackers who need a mid-sized reservoir that balances capacity with packability. It’s a good choice for multi-day trips where saving space and weight matters, for winter outings where better freeze tolerance is helpful, and for anyone who prefers a simple, durable bladder with a versatile 3-in-1 cap. MSR backs this product with a three-year limited warranty and it is made in the USA.