If you're trying to achieve a traditional look on your chopper or antique motorcycle, modern silicone plug wires are going to look out of place—especially the real large gauge ones.
These braided cloth wires are the solution if you've got a twin. These feature preinstalled 90° boots on either end for the spark plugs. All you've gotta do is measure your existing wires, cut these where appropriate, install the included 180° boots, and crimp the ends on.
Total length is 40 inches, which is long enough to cover most P-twins (Triumph and Yamaha) and V-twins (Harley-Davidson and most metric). If you've got a four-cylinder machine, just order two sets.