14s is a surface mounted light fixture with a 2.2″ (55mm) diameter mounting plate designed to be mounted on walls and ceilings. Please note, the 14s does not attach directly to a junction box and the transformers must be remote mounted. 14sp has a paintable 4.5″ (115mm) diameter mounting plate designed to be mounted on walls and ceilings, directly to a standard junction box (not included). It is also IP65 designated meaning that the 14sp can be used outdoors and in other wet environments. LED lamping for 14s is not dimmable.