Seattle Cyclerwrote a review of Castelli Arm Skins on July 15, 2017
I purchased the men's small/medium size for my slim female arms. The bicep band is elastic wrapped in soft material. There is not any silicone dots or lines on the band against the skin. Feels very nice, but will see how they stay up on the arm while cycling. The wrist band is similar construction.
The arm material is soft and not a silky sheen as with other brands. Not having used them yet, it will be interesting to see if these feel cooler than the nylon-type sheen materials used by Novarra (REI) and Castelli.
The LENGTH is certainly shorter than Novarra and Castelli. I have longer arms and it just reaches my glove.