Here's what other sites are saying:
The Infiniti half-zip top from Brooks works hard to keep you comfortable on cool days, and it excels under a shell during cold weather. Moisture-wicking, quick-drying polyester offers soft stretch, top-notch performance and high mobility. 9.5 in. front zipper offers instant ventilation, and a stormflap shuts out chilling drafts. Thumb holes hold sleeves in place when arms are in motion and keep wrists warm. Zippered arm pocket stores small items such as a key or debit card. Reflective highlights enhance visibility in dim light from any angle. The semifitted Brooks Infiniti half-zip top is not too tight and not too loose.