And here is what Salsa has to say:
The EXP Series Direct Mount Thumb Screws allow for quick and easy attachment of Salsa EXP Series Direct Mount Packs to bicycle frames equipped with direct-mount locations.
- Can be installed and removed by hand or with allen key
- Includes necessary 0.5 mm washers and 4 mm spacers
- Sold in packages of two
Our clear and concise specs will be ready soon.