Up for sale is HARDDRIVE 2018-2019 FXFBS Softail Fat Bob 114 Harley Davidson MIRROR EXTENSION KIT BLACK 270834. The vendor part number is 270834. Please read the title to know what is for sale. Catalog Description�. These new mirror extension kits improve visibility to the rear of your bike by repositioning mirrors outward approximately 2" and upward 1". Available in a chrome or black finish and made from billet 6061-T6 aluminum. They fit a wide selection of original mirrors for '06 later Dyna, '08 later Softail and '09 later Road King models.