With the Sierra Long Sleeve Zip, merino wool specialists Icebreaker have created a luxurious-feeling mid layer at a luxurious price. It is made from a 260-weight merino wool, which is their middle-of-the-range weight fabric. It is brushed on the inside and feels very soft and cosy. This is a cool weather piece and I’ve enjoyed wearing it through the autumn and winter under a waterproof (and quite large parts of the rest of the time too). It would be too hot in summer. As with all Icebreaker garments, the wool can be traced back through the supply chain to the farmer. There are two hand-warmer pockets and a small chest pocket – a bonus in my mind – and a hole for your headphones. It’s also one of the better tailored pieces reviewed here, and naturally snug. There’s a zip ‘garage’ so the zip feels comfortable against the chin – and it needs to be because it comes up reasonably high – and there’s an internal baffle on the zip. I’m a fan of merino wool tops, and this is a great piece… at a price.