Page 61 - D. Raleigh "Knots and ropes for climbers"

You can use buy sewn runners, which are slightly stronger and sleeker than knotted ones, but you
can't untie and thread them through fixed anchors, tunnels in the rock, or around trees. Whichever sort
you prefer, wear them on your shoulder, cartridge-belt-style.

The number of single runners you'll need depends on the sort of climbing you're going to do. Sport
climbers will need only two for anchoring at belay, lower, or rappel stations, whereas big-wall
climbers can need twenty. As runners are inexpensive and lightweight, it's better to carry too many
than too few.

A double runner used to equalize two anchors.
Note that you must secure each side of the sling with an
Overhand on a Bight (step 4) in order to prevent a
shock load should one of the anchors fail.

Double runners are twice (or three times) as long as single runners and are used mostly to string
together belay, rappel, and top-rope stations. A couple of these are usually adequate for any situation.
If you use your long runners primarily for top-roping, make them from 1-inch tubular webbing, which
cuts less readily than the thinner stuff.

Quickdraws

Quickdraws are short, 4- to 6-inch straps of webbing used to clip bolts, or nuts or cams when the line
is straight and rope drag won't be a problem. You can tie quickdraws from a couple feet of 9/16-inch
tubular webbing, but since quickdraws are too short to thread through anything anyway, the less bulky
sewn versions are superior. Sewn quickdraws are usually made from flat webbing and have a rubber
band or gasket to trap the bottom carabiner. Most sport climbers own about two dozen quickdraws.