CastelliPro Seamless 2 Arm Warmer(Return to Product Page)

Perfect for those cooler (but not cold) days. Size guide on the Castelli website is accurate. Easy to slip on and so far, it stays in place well. Best for temperatures from the mid-40s to around 60F (7-15C), maybe to 65F (18C) at a pinch. Anything colder, and you probably want the heavier version (Thermoflex 2), if not a well-insulated base layer. And I could probably go without at warmer temperatures.

The warmers are really compact and if needed, would be a breeze to peel off and tuck away in my jersey pocket as it warms. Price on BTD was excellent--all in all, a great year-end gift to myself.

I love these, they pack up incredibly small and do a good job keeping my arms warm.

These are not wind blocking or thermal so they work best on mid temp days

I love these, they pack up incredibly small and do a good job keeping my arms warm.

These are not wind blocking or thermal so they work best on mid temp days

Stretch to fit, comfortable to wear and keeps warm without sweating.

These are great for when you don't need a thermal arm warmer and just enough to keep you warmer on cool days and pack up smaller than any other arm warmer I've ever had.

These arm warmers are exactly what I wanted. They're light and roll up small, yet they're surprisingly warm. I have some other-brand arm warmers that work well, but they are stiffer, heavier, and not much warmer. They have seams, so you need to get them on just so. The wrinkle a bit in the inside elbow, so they aren't as comfortable.

A nice thing about these sock-like warmers is that you can just roll them down to the wrists for the climbs and back up for shady descents. No need to take them all the way on and off over gloves.

Also, these stay smooth and don't wrinkle or bunch up, so they stay aero.

They stay up just fine, but I use a trick: smear a light layer of Vaseline on arms/legs where you want the warmers to stay up, and they won't slip down. These warmers stay up pretty well on dry skin, but I always use my trick before riding for 100% reliability. I hate when warmers slip during rides!

These are really perfect for cool and variable conditions. And they do surprisingly well down to the high 40s (~9C).

The product has changed over the years. Fit and design better 5 years ago. Getting disappointed in their product and fit.

Very simple arm warmers - like them so much I also ordered the seamless leg warmers.

Castelli nailed it with these seamless leg, knee and arm warmers. They must use a very high loft insulating fiber to knit them. They are super soft, stretchy and very warm for their weight and thickness. Although they look small when you get them, they stretch a lot. And thus far have not lost their shape or rolled down.

Surprisingly warm and very comfortable. These are short for me (I wear 36-37 in. dress shirt sleeves) -- even shorter than other arm warmers that I wear -- but I still like them when a need something mid/light weight for 50-60 (F) temps

Over the years I have used Pearl Izumi pro thermal arm warmers. Those are great but I always wanted something that was a touch less warm and more breathable. I found the perfect pair of arm warmers in the Castelli Pro seamless 2. They provide just enough warmth for nippy fall days, but are much more breathable than my pearl izumi ones for hard intervals. Also, I thought that it couldn't get more comfortable than the pearl izumi ones, but these are even more comfortable, and they are very well constructed with a very engineered fit. Highly recommended.

I never ride in the sunny and warm season anymore without wearing arm sleeves. It's the best "sunscreen" application there is.