And here is what Salsa has to say:
The Salsa EXP Series Rubber Strap is a strong, adjustable strap that holds your gear securely to Salsa Anything Cages, Anything Cradles, or racks. Use them anywhere you need to secure a load on your bike.
- UV- and weather-resistant
- Includes band to keep excess strap out of the way
- Sold in pairs
- 22” length is best for use with Salsa Anything Cage and Anything Cage HD
- 30″ length is best for use with Salsa Anything Cradle