Ultra-Sil Compression Dry SackSale
BEST USE: Backpacking
WATERPROOF? The body of the dry sack is more than adequately waterproof (2000 mm hydrostatic head) for the intended use (storage inside a backpack or duffle).
DIMENSIONS: 8 x 18 inches
WEIGHT: 3.2 oz | 90g
Shipping & Returns
Our warehouse is actively shipping orders from 8am to 1pm MST Monday through Friday. Most orders ship in one business day, but the transit time can take up to 7 days, depending on your distance from Boulder, Colorado.
2nd Day and Next Day Air orders will ship same day if placed by 1pm MST, Monday-Friday (except holidays).
All orders are eligible for fast and easy returns within 60 days of purchase.
For more details, please check out our Help Center
The Ultra-Sil Compression Dry Sack is a super lightweight dry sack designed to compress sleeping bags or bulky clothing and keep them dry. It is designed for use inside a pack or duffle bag – the featherweight fabric is not intended for external use. Made from Ultra-Sil 30D CORDURA® Nylon fabric with an eVent® fabric base, air can be squeezed out by tightening the compression straps, but the eVent fabric keeps water out.
It's an ideal part of a modular packing system: quality fabrics, taped seams a hypalon roll-top, non-wicking closure with a Field Repair buckle keep the Ultra-Sil Compression Dry Sack light and functional
An incredibly lightweight yet durable fabric used in a large number of Sea to Summit products. This 30 denier Nylon is made with CORDURA® yarns for strength, woven into a ripstop pattern. Two versions of the fabric are used:
- Water-resistant products (such as the Ultra-Sil™ Stuff Sacks) are siliconized on both sides for ultimate packability
- Waterproof products (such as the UltraSil™ Dry Sack are) siliconized on the outside and PU-coated on the inside to allow seam taping.
- Both versions have a hydrostatic head greater than 2000mm – which makes them more than adequately waterproof for the types of environments they are intended for.
eVent™ fabric is an air-permeable, waterproof laminate used in two different functional areas in Sea to Summit products:
- In the base of our best-selling eVent Compression Dry Sacks, Evac Dry Sacks and Ultra-Sil™ Compression Dry Sacks. In this application, the laminate utilizes a 40 denier nylon face fabric: the material allows air to be pushed out of the dry sack/compression dry sack but prevents water from entering. This means you can compress the air out of a dry sack without needing a purge valve! In the upper section of our Quagmire and Alpine Gaiters. In this application, the laminate utilizes a 70 denier nylon face fabric. The material allows perspiration to pass through easily but prevents external water from entering. The result: waterproof protection and superior breathability!
Cordura® is a special type of nylon yarn used for its strength. These yarns are used in two different product areas:
- In the siliconized Ultra-Sil™ fabrics used in Ultra-Sil™ Dry Sacks, Stuff Sacks, Compression Sacks, Pack Covers, Travelling Light and Travel Essentials products
- In the foot section of the extremely tough eVent® Quagmire Gaiters.
Best UseBackpacking, Hiking & Bike Touring (used inside a bag or pack)
ClosureWaterproof roll-top closure with lid and compression straps
Material(s)Ultra-Sil nylon body and eVent fabric base
MeasurementLength - measured with roll-top closure open Volume - measured with closure rolled 3 times
Repair Buckle Size5/8in | 15mm (2-Pin)
ShapeCylindrical with round base for easy packing
WaterproofMore than adequately waterproof for use inside a pack or duffel
|XXS / 3.3 liter||XS / 6 liter||S / 10 liter||M / 14 liter||L / 20 liter|
Frequently Asked questions
Is this compression sack suitable for bikepacking?
No. Bikepacking subjects bags to a lot of sharp and abrasive elements. The featherweight fabric is simply not designed for sharp points or rough surfaces. We recommend the Nylon eVent Compression Dry Sack for this use.
Is this compression sack worth the weight and cost?
Once you have experienced modular packing with ultralight compression sack you’ll wonder how you ever lived without them.
Is this compression sack a good tent storage bag?
Perhaps. Carrying the tent canopy in your pack (with the poles under the compression straps) is a great idea. However - the canopy may not compress that much.
Is this compression sack waterproof?
The body of the compression sack is waterproof enough (2000 mm hydrostatic head) for use as storage inside a backpack or duffle.