Face mask - useful on high and wind blown ridges and glaciers. Carry between 1 nd 2 litres. Wrapping duct tape around water bottles ensures that the tape remains usable even in cold weather. Headlamp - with spare batteries and bulb. Ice Tools - One, if the terrain invoolves little steep ice.
Plastic boots are better for winter or steep ice routes.
Harness - I t is an asset if you can put the harness on while wearing skis or crampons and if you can go biffy while wearing it. Biners - Locking biners that accept Munter Hitches are usful for lowering and top belays. Group Equipment Ice screws, pins, cams, nuts, slings, biners, Abalakov device - depending on the route. Double ropes are only marginally heavier than a single 10 or 11 mm rope, but give more flexibility, making for quicker rappels and allowing the leader to belay two seconds on separate strands. By pulling it over your head and under your seat, you create a weatherproof shelter.