The Jannu pants are polyester with a touch of Spandex, this gives them a four way stretch which is great for steep climbs and gives you pretty much unrestricted movement. The baggy fit helps with this, but personal preference is for a more fitted look.
At the ends of the legs you'll find zips which help when taking the trousers on and off over boots and perhaps more importantly to get the right fit over the tops of your boots.
The summer weight fabric feels breathable and is good for 3 season use, or at a push for British winter when combined with a heavyweight base layer.
The waistband is comfortable with a popper fastener and belt loops. The lining feels good next to the skin and the gusseted crotch and articulated knees ensure that the trousers move with you.
The double weave fabric is intended to be durable but being summer weight and having no reinforcement patches we would expect some wear with heavy and extended use.
The two zipped hand pockets have cosy fleece linings for those particularly chilly days when you forget your gloves and there's an additional zipped cargo pocket for small items.
Overall the Jannu trousers are a decent, if uninspiring effort from Sherpa, at £80 they place towards the top end of the price range where there are some fairly compelling alternatives.