Sea to Summit Ultra-Sil Compression Sack



The small version of this sack allows my daughter…

Rating: rated 5 of 5 stars
Source: bought it used
Price Paid: $15.50 on ebay


The small version of this sack allows my daughter to carry both her sleeping bag and pillow in the bottom zipper compartment of her TNF Terra 45 pack. Durable, slippery material squeezes right in.


  • Durable rip stop style codura ultra-sil material
  • Lightweight
  • Slippery material makes putting in/pulling out of pack easier


  • None

Basically, the pictures tell the story:

Here's the Kelty Cosmic Down 20 degree bag in its storage sack.


Here it is in the Sea-to-Summit uncompressed (compared to a Nalgene bottle).


And in its final compressed state.


One of my twins is fairly slight in stature (98 lbs) so her pack is The North Face Terra 45.  When her sleeping bag was stuffed in the sack it came with, it took up the complete zippered compartment in the bottom of her pack. Since she was already limited in space, we decided to try this S2S Ultra-Sil Compression Sack.

(Note: I have a couple of Granite Gear compression sacks I've used over the years but they are made of a heavier weight material and I'm thinking of getting the medium version of this sack for my sleeping bag. The weight difference between the Ultra-Sil and the regular Granite Gear material is quite noticeable.)

I'm interested to see how the material and the seams hold up over time since it is more delicate. The material has a rip-stop type of weave so even if it gets a hole in it I think it will resist getting larger.