This article is from the Bicycles FAQ, by Mike Iglesias with numerous contributions by others.
Available in a huge variety of sizes, of which the Carradice bag is a
premium version. Carradice is a brand name for saddle bags. They offer
models ranging from small up to pannier-competition.
The ordinary smaller versions are absolutely essential for the
emergency tools, spare tube and patch kit, or spare tire for the sewup
set. They are also very inexpensive. For larger loads and bags please
see the Carradice bags review.