Nylon Cable Ties.
Here's some information about them:
Product Type: Nylon Cable Tie, also known as zip ties or hose ties.
Specifications: The pack contains 100 pieces (PCS) of black nylon cable ties with a size of 5x350 mm.
Material: They are made from Nylon 66, which is UL recognized and has a UL Flammability rating of 94V.2.
Usage: They are commonly used for securing wire bundles and harness components, as well as for general fastening of items.
Caution: The packaging advises, "(DO NOT OPEN UNTIL READY FOR USE)