The biggest selling point on the Pin Ears SL is that it has done away with zippers altogether. Most bags use at least one – and sometimes two – zippers to seal themselves up and keep the person snuggled up inside warmer. But, zippers also add weight, have a tendency to malfunction, and can create excess noise that wakes other campers inside the tent. Big Agnes overcame those issues by creating a clip and loop system that effectively seals up the bag nicely, while shaving ounces from its overall weight. This system is also easy to use and is virtually silent too.
So just how much does this sleeping bag weigh? The Pin Ears SL comes in at 2 pounds, 2 ounces (964 grams) for the regular version and 2 pounds, 5 ounces (1.04 kg) for the long model. That isn't the lightest sleeping bag I've ever come across, but it is certainly in the ball park and is definitely a respectable number. Particularly since this bag is rated for 20ºF (-6ºC) and stuffs down to a very small size.
Without a zipper some campers will probably concerned that cool air can still make its way inside the bag. But Big Agnes has designed the Pin Ears with a cocoon like construction that keeps warmth in and cool air out, making it just as comfortable as any normal sleeping bag that I've used with a zipper. In fact, other than using the hook and loop system, I didn't notice much difference in terms of overall performance, although it was nice that the bag was quieter when getting in and out.
Other nice features of the Pin Ears SL include a vaulted foot box to give your feet a little extra room, which can sometimes be at a premium in a mummy-style bag. The bag also has interior loops for attaching a liner, which is great for adding a bit of extra warmth, as well as an exterior half-sleeve for connecting to a sleeping pad too. This prevents the Pin Ears from sliding around too much, and allows the person inside to move about more naturally without fear of rolling off their pad. Thanks to plenty of interior space, it is even possible to sleep on your side if you choose.
Big Agnes has given the Pin Ears 650-fill power of insulation by way of water-resistant DownTek down. This makes the bag a much better option when used in wet and cold environments, and quite frankly, I'm not sure why you'd buy a sleeping bag (or down jacket) that isn't using hydrophobic down these days. The difference in price is negligible, but the difference in performance is enormous. If you take your backcountry or adventure travel excursions seriously, you'll definitely want this material in your important down products.
If you're in the market for a new sleeping bag and are looking for something that is lightweight, easy to pack, and takes up very little room in your backpack, the Pin Ears SL 20 should be on your short list. Its zipperless design shaves ounces off of traditional models, but still provides the warmth and comfort you need on cold nights in the tents. The hook and loop closure system performs nicely and still manages to keep warmth in, while the interior of the bag is spacious and very comfortable.
Priced at $269.95 for the regular and $289.95 for the long, the Pin Ears SL 20 is about at the middle of the road in terms of price. Yes, you'll find 20º bags that cost less, but very few of them will offer the same weight-to-warmth ratio, nor will they deliver in terms of overall performance. The few extra dollars that you pay for this model will pay off in the field, making it a great choice for backpackers, through-hikers, and adventure travelers for sure.