The Problem Solvers Sheldon Fender Nut was designed to replace the standard brake nut and allow convenient fender (Mudguard) mounting on steel and aluminum road frames and forks.
Essentially, this is a long brake nut for road forks, as it allows the road brake nut to thread into it for brake mounting. But, it also has threading inside so that a fender mounting bolt can be threaded into the back of the fork.
The PS Sheldon Fender Nut comes as a set of two sizes: 10mm for rear mounting and 13mm for front forks or 10mm Rear, 32mm Front
The fender nut will work with all steel and aluminum frames and forks; it also will work with some carbon forks, but check first. It will not work with forks requiring an extended brake nut or a narrow brake nut.