Do these fit a 99 Harley soft tail custom
By D
These are suitable for pretty much any 12V application, including your Softail. Some minor electrical work is required to complete the installation. Other than that, you just need to find a flat surface that measures at least 1-1/2" x 6" x 1" to drill and mount these signals. They're held in place by the two mounting bosses you see in the photo.