Choosing a Crampon
Crampons help climbers ascend by allowing them to kick into the ice. The use of the crampon determines what materials it is made from. Lighter weight crampons often used in ski touring are made from aluminum and though they are not nearly as strong as steel crampons, they do save weight. Steel crampons are heavier, but more reliable and they are used for general mountaineering and ice climbing.

When you are buying crampons make sure that its features are well suited to the boot you will be using. If you decide you want a step-in crampon, you're going to require a boot that has front and rear welts. Their are many crampons on the market that have been designed for specific climbing styles, so you may require a few different pairs to do all the activities you want.
Full Article