Slumberjack  Sleeping Bag Liner - Cooling

To start, I will admit that I have not yet actually used this liner at all, but I do have some thoughts about it that I felt worth sharing. First of all, compared to three other sleeping bag liners that I own of various designs, materials, and price points, this one is by far the largest and bulkiest! I've included a comparison photo of this Slumberjack liner in its stuff sack next to both my decade-old Sea to Summit Coolmax liner and a 21oz bicycle water bottle. I was honestly surprised to see that the Slumberjack is twice the size of the Sea to Summit, and it's pretty tightly rolled up in that stuff sack! I haven't fully removed it from the stuff sack because of how tightly it's rolled up and packed in there, and I'm worried that I would never be able to get it back in! XD Suffice it to say, this is not one that you'd want to take backpacking (or even bikepacking) due to its size. That being said, the material does feel nice, just like a favorite soft t-shirt, although I obviously can't speak to its "cooling" quality. I'm sure it would make for a decent liner for car camping in warmer weather, or even as a lightweight "sleeping bag" on its own for those hot, sweaty nights when a full-on regular sleeping bag isn't really necessary. If I end up keeping it, I could imagine using it for that purpose, or perhaps for a bit of added comfort while lying in my hammock out in my backyard. We'll see.