Several listings are labeled trial/mini/travel or feature compact, foldable designs that make them suitable for travel.
The listings recommend washing the brushes with soap and water and then air-drying them.
Results include detangling/cushion brushes, styling (banana) brushes, a mini heated straightening brush, compact foldable detanglers, and makeup blush brushes.
Lengths are listed from about 1.62 inches up to 9 inches; widths range from about 1.75 inches to 2.62 inches across the shown brushes.