Design thinking toolkits are assembled supplies of low fi materials you can use for brainstorming and early prototyping.
Materials in a kit can include (but are not limited to) the following:
Aluminum foil, duct tape, Post Its (recommended), index cards, dowels, ping pong balls, sticky tack, string, sharpies, rubber bands, tacks, paper clips, pipe cleaners, twisty ties, scissors, clay and more.