Opened it and went down the hall to the closet for a spare bulb.

Comes with a spare bulb.

Beyond that, each caver should have two backup sources of light, like flashlights, as well as spare bulb and electrical tape and wire for repairs.

Drummond managed to amass a stockpile of more than 600 spare bulbs, which were carefully stored for judicious future use.

Other good features include a spare bulb in the tail cap and a useful key ring facility.

If you take your own car, pack a warning triangle, reflective "vest", first-aid kit and spare bulbs.

The whites had found spare electric-light bulbs valuable currency in dealing with the redmen.

He went to look for a bulb to replace it; found the spare bulbs, too, were missing.

He was quite sure that a day or two previously there had been spare bulbs in the drawer.

Some events specifically require riders to carry specific equipment (e.g. lights, spare bulbs, reflective clothing), though this varies depending on the organiser.