From ShaveWiki
A Dopp kit is a small toilet bag, made of leather, vinyl, or cloth, that is used for storing men's grooming tools for travel. Common items kept in a Dopp kit are deodorant, a razor, shaving cream, comb, shampoo, nail clippers, scissors, toothbrush, toothpaste, and cologne. The name derives from early 20th century leather craftsman Charles Doppelt, a German immigrant to the United States, who invented his toiletry case in 1919.
The kits became widely known during the Second World War when they were issued to GIs. Doppelt's company was purchased by Samsonite in the early 1970s.
Dopp kits were once a common gift given to adolescent males as they ascended from boyhood to adulthood.
Although the term was originally a trademark and may still be, it appears to have at least mostly become generic.
In British English/England the item is known as a "sponge bag".
