Thomas C.wrote a review of Castelli Climber's 2.0 Full-Zip Jersey - Men's on July 29, 2019
First off this is a skin tight highly breathable jersey anatomically designed to hold tight on the tops or in the drops. It will be slightly tight in the shoulders when dry, get your sweat on and it all clings and relaxes, no flapping, the waist stays put with full pockets that don't sag. Sleeves reach 2/3 down my bicep and stay there. I like there are light colors to choose from.
Sizing, if you wear a medium t-shirt get a large it will fit perfect.