Basically your good old zipped hoody brought up to date and made bike friendly, the Therminal Mountain jersey is constructed of soft and stretchy Specialized Therminal fabric, with a brushed fleece back. A three panel hood with drawstring closure can be pulled on if the temperature drops and there is one chest and one side pocket for small items. Thumbloops mean it should never ride up your arm, and elasticated drawstring at the hem finish off the features.
We have had the Therminal Mountain Jersey for a number of months now, through a fairly chilly winter, and have rarely come across a garment we have liked more. It is at home as much off the bike as on, and in fact that is where we have used it most - apres ride and down the pub.
That doesn't mean it isn't effective on the bike too, but it really is a cosy and comfortable thermal layer that is regularly too warm if you are working at all hard, so it is largely kept for social days out mountain biking between cafes or days where there will be a lot of hanging about in the cold.
The beautifully stretchy and soft Therminal fabric has a knitted front and brushed fleece interior, so when you pull it on you really don't want to pull it off again any time soon. We pull the hood up when damp helmet hair is getting chilled and use the thumb loops to draw the sleeves low over our hands. Combined with the long body coverage and drawcord adjustable collar and we are sold.
Get one now, it will soon become the hardest working jersey in your wardrobe when summer fades.