From Lowbrow Customs: Mount your solo seat easily with these weld-on solo seat spring mounts. Made of 1018 cold rolled steel for easy welding, they are 1" diameter with a threaded 3/8"-16 shaft for the spring to sit over. They are coped at 1" to fit standard size frame tubing, but can easily be enlarged to fit larger 1 1/4" tube if necessary. Included are a heavy-duty chrome steel washer and a chrome nylock nut for each mount to secure your seat springs to your frame. Price is for a set of two mounts, two washers and two nuts.