Brand: RAM Mounts Manufacturer's Part Number: RAM-B-342U Part Type: Mobile and Media Device Mounting Accessories Product Line: Ram Mounts Motorcycle Fork Stem Mounts Summit Racing Part Number: RMI-2581 UPC: 793442906213 Mobile Device Mounting Accessory Type: Ball base motorcycle stem mount Ball Diameter (in.): 1.00 Quantity: Sold as a kit. Notes: Fits into cylindrical bore wall of fork stems that measure from 12-20mm， 28mm and .5 in. to 1.10 in. Certain motorcycles require adding electrical tape to the area of the plug that is the largest diameter until it fits snugly in the stem. Ram Mounts Motorcycle Fork Stem Mounts One of the cleanest ways to mount small electronics on your motorcycle is Ram Mounts motorcycle fork stem mounts. Simply slide the assembly into the hole of the stem and tighten the machine screw to create a tight fit. Ram Mounts motorcycle fork stem mounts are designed to fit into the cylindrical bore wall of fork stems and will work with stems that measure from 12 to 22mm and 28mm or 0.5 in. to 1.10 in. at the following intervals.Metric:* 12mm* 14mm* 16mm* 18mm* 20mm* 28mmStandard:* 0.50 in.* 0.55 in.* 0.63 in.* 0.71 in.* 0.79 in.* 1.10 in.