Rucksacks

1. Main Compartment

A capacity of about 65-80 litres is a good size for long silver/gold expeditions and will also come in handy in winter, with space for spare clothing, a head torch and even a larger flask. Tall, slim packs won't obstruct the arms, but can nudge against your head.

The opposite happens with broader, shorter packs. Very square main compartments are easy to pack and access, but tend to hold the weight further away from your body. Traditional lid and drawcord packs are reliable, but can sometimes be awkward to pack. Zip openings offer easier access, but the fastenings can break.

Your back soon gets sweaty with a rucksack resting against it. Concave 'airflow' back systems help combat this by holding the pack away from your body, with pads at the top and bottom being the only points of contact.

This is the coolest system but it is heavy, and it holds the load further away from your body, and it can also make the rucksack harder to pack. Channelled backs are a good compromise. Women's packs usually have shorter back systems.

Look for some padding on straps that have contact with your shoulders and hips. Also check that the chest strap can be easily adjusted and that it sits comfortably - this is especially important for women.

Compression straps are a big plus, as they tighten the load down, keeping it secure and stable even when the pack isn't full.

Check that there's a suitable pocket for a hydration system (if you use one), and also that there's a hole for the drinking tube.

Other useful features include walking pole attachments, side pockets and a rain cover.