Halo "Fat Foot" Cog Halo Fat Foot. Note that these are gears with a Shimano HG fit with a 7mm base width. These can not be used on normal track nuts. Singlespeed Use for singlespeed in combination with a single-speed spacer kit. Fixedgear The only hub that we have in our range where they are applicable as a fixedgear is the Halo Fix-G Track hub (see second image, of course not included in delivery). Properties - CNC machined Cr-Mo gears - 1/8 -7mm wider HG type spline foot - Chrome plated