The Proof 72-Hour Merino T-Shirt is just $58 during this sale, which lasts through Monday. It's received around 700 five-star ratings from customers and has a nearly perfect review score. At this point, only two of the six available colors have most of the sizes still available -- a testament to how beloved this style is by shoppers -- but we expect all sizes from XS to 3XL to sell out completely by Monday.

Proof 72-Hour Merino T-Shirt, $58 (was $78) at Huckberry

Like other Proof 72-Hour gear, the magic of this T-shirt comes from its blend of 87% merino wool and 13% nylon. Merino wool is meant to be worn close to the skin, naturally resists odors, and is quite breathable. The Proof 72-Hour blend is also, as the name suggests, good for continuous wear without needing frequent washes, and is even rated UPF 30+ for sun protection. When put all together, this material makes the Proof 72-Hour Merino T-Shirt feel incredibly soft and comfortable, whether you're out for a hike or wearing it for travel.

One shopper discussed the quality of the fabric, assuring that it is "exactly what it says it is." They said, "I had an upcoming trip, so I bought myself a 72-Hour Polo and a 72-Hour T-shirt to keep the packing a bit lighter. I had to try wearing it for 72 hours, and yeah, it works. I even slept in it, and it looks good, smells fine. The wool blend is great quality and looks like it will hold up over time."

Proof 72-Hour Merino T-Shirt, $58 (was $78) at Huckberry

Another shopper talked about how it holds up throughout the day, as well as imparting some practical upkeep advice. "It's a versatile shirt that is light and comfy. Pretty good against wrinkles," though they noted that "it does shrink when placed in the dryer," so make sure to let it air dry.

Based on our experience of past sales, we expect this Proof 72-Hour T-shirt to sell out before the sale ends, so if you want one for $58, don't hesitate to get your order in soon.