I/O Bio Merino Contact Boxer Brief - Men's - 2009 BCS

I love the softness and comfort of these briefs. I may fit a Medium better than the Larges that I have. My waist is 33" and the Larges are the slightest bit loose but don't fall down. I am interested to find out how long they last. The waist band feels stout enough to last a while. The fly functions well. The hand on these is exceptionally soft and supple. Very comfortable briefs that my wife says I look sexy as hell in.

Bottom line: Great brief that won't smell from perspiration alone after one or two uses. Soft as a babies bottom!

these are great

only had these a few days but lovin em so far. barely tell I have em on. didnt give them a five until i see how they hold up to trail life and multiple washings. my first and only pair of Smartwool skivvies disintegrated like wet TP in a windstorm. the wool content in the IO doesnt appear to be the same as SW but that may be a plus. time will tell. is that TMI for a pair of undies....

I had to find a new style of briefs to wear after REI changed the design on their in-store brand. I wore the REI's for years, but when they changed the design, I hated it, along with everyone else who commented. I wear these everyday, so I have about 10 pair. They are comfortable and seem to be durable, but time will tell. They are the best fitting I have had. They dont even seem to ride up my legs after all day use- without being tight like spandex. The material is very soft and feels good against the skin. The only thing I wish I/O would change is to stop putting a tag in the garment. It would be much better to just print the info. I rarely feel the tag, but physiologically, I know it is there.

Great except no fly

Overall, great pair of undies, especially under $30 for wool (on sale). Very thin...almost a guaze-like feel (lighter weight than Smartwool), but seem durable enough (will let you know after a couple of seasons of hunting). Unfortunately, if you order black, you do not get the style with a fly as pictured on the website. The older style (w/ fly) has a slight bit thicker material all around and double in front (which can be helpful in really cold mornings), and doesn't "conform" around (and inbetween) everything as much as the newer non-fly styles shown do.

Marked down one-star for picturing black in the older, thicker material style w/ fly but receiving the newer thinner style. Plus, that tag can get really annoying when you start to sweat.

Recently got my first pair of these babies and they are top notch. They span the spectrum of utility as I've used them as a base layer for alpine skiing and under my suit pants for work. They deliver comfort and breathability in both realms. I'm 6'5" 215 and went with the XL based on reviews and the waist band is a touch loose to be picky. My next pair will probably be a large. I have multiple pairs of patagonia boxer briefs and the IO Bios are more comfortable and don't ride to high in the saddle.

My favorite undies…ever. I bought my first pair 4 or 5 years ago. I buy a new pair or two for myself each x-mas, slowly building my stock pile of wool underwear. I recommend them to everybody (well, anybody who will listen to me talk about my underwear). I wear them all the time. I wear them every time I’m snowboarding, winter backpacking, summer hiking/swimming, long weekends without showers available, etc. They seriously don’t stink, don’t chafe, and they support the junk the whole weekend through. Plus, they dry quickly. My oldest pair has a waist band the folds, but the rest don’t. I prefer the ones with the front opening; they ride up in the back less than the hole-less ones. I/O Bio are my favorite of all the merino wool undies out there.

These go way into the crack. I thought without a seem running straight down the crack like some other boxer-briefs have these wouldn't go spelunking, but they go deeper than anything I've every worn.
On the plus side, the material is great.

These are very comfortable. I also have the heavier and silkweight smartwool boxers, and these are somewhere in between as far as thickness. I like the fit at least as much.

I bought these for my boyfriend and he seems to like them however he noted that they aren't as thick as the merino on the icebreaker or ibex shorts. They look great and are very soft, I'd recommend.