Lighting fixtures that include fixture housings and light-emitting diode (LED) modules configured for tool-less attachment and detachment to the fixture housings are disclosed. Certain LED modules include LED emitters, corresponding electronics for operating the LED emitters, and at least one shaped protrusion. Certain LED modules include safety tethers that are configured to provide mechanical support during the tool-less attachment and detachment. Lighting fixtures include a lens and removable endcaps that secure the lens to the fixture housing. Certain lighting fixtures include a backup battery and a button provided in one of the endcaps for testing the backup battery. Certain lighting fixtures include a cut-out portion in the fixture housing corresponding to the shaped protrusion of the LED module for providing identification of replacement LED modules that may be attached to fixture housings.