These Bump Spring cups are made with an offset retainer base design that sits down over the jam nut to allow for more travel where space can be an issue. Not designed for use with foam or rubber style stops.
     Short offset gives 1/2" more space over a standard bump cup assembly. Tall offset gives 7/8" more space over a standard bump cup assembly. See picture of all 3 side by side.
     Standard Body 2.25" ID x 3.0 Deep and Small Body 2.0" ID x 2.75" Deep versions. 
     Choose standard or small body, short offset, tall offset retainer - 1/2" shaft only.