PACK SIZE: Fits a 15 to 30 liter pack
PACKED SIZE: 4 x 2.5 in | 10 x 6 cm
WEIGHT: 2 oz | 57 g
RECOMMENDATION: If you stow any gear externally on your pack, we would recommend buying a Pack Cover a size larger than normal.
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
An incredibly lightweight yet durable fabric used in a large number of Sea to Summit products. The 30 denier bluesign Approved nylon is made with CORDURA® yarns for strength. A Non-PFC DWR finish on the outer face helps to shed water.
The inside is polyurethane-coated – in dry bags, the seams are seam-taped.
The hydrostatic head is greater than 2000mm – more than adequately waterproof for the types of environments Ultra-Sil dry bags, stuff sacks and compression sacks are intended for.
Cordura® is a special type of nylon yarn used for its strength. These yarns form the heart of the siliconized Ultra-Sil™ fabric, used in:
- Storage products: Ultra-Sil™ Dry Bags, Ultra-Sil™ Stuff Sacks, Ultra-Sil™ Compression Sacks
- Camping/Backpacking Accessories: Ultra-Sil™ Pack Covers, Ultra-Sil™ Folding Bucket and Kitchen Sink
- Travel products: Garment Mesh Bags, Toiletry Bags etc
- Travel Essentials: Ultra-Sil™ Daypack, Ultra-Sil™ Dry Daypack, Ultra-Sil™ Shopping Bag
Best UseUltralight Backpacking
Material(s)30 denier Ultra-Sil™ nylon
Frequently Asked questions
Aren't most backpacks waterproof without a cover?
No. Water will enter through seams and zippers (especially in really wet parts of the world)
Why choose the Ultra-Sil Pack Cover over the Nylon version?
The Ultra-Sil Pack cover is slightly lighter and has a smaller packed volume - it is more suitable for weight-conscious backpackers
Will a pack cover make my pack completely waterproof?
In most cases, waterproof enough - wind-driven rain can still enter through the space between your back and the harness