Salsa 197 mm Flat Thru Axles
About Salsa - "At Salsa, we believe a sense of adventure makes life better. The bicycle can be so much more than just a bike; it's a path to new places, new people, and amazing experiences."
The length of the axle from the base of the head to the end of the threads, in millimeters.
Usually flat or conical. This is the shape of the washer and should match your frame or fork.