The Allegiant lightbar from Federal Signal is an ultra-low profile lightbar that entered the market around 2018. It utilizes their popular SpectraLux LED/optics technology which provides unparalleled brightness, and ROC circuit boards which are consolidated for easy repair/replacement. Each lightbar is controlled with a SIM serial module (sold separately), and the "FS Join" models (when available) can be synced with a Pathfinder or similar siren/controller for even more customizability. 
 
Wiring: 12V DC power/ground, CAT5 data cable (SIM/serial module required; Link here)
Mounting: Includes mounting feet, straps not included
Dimensions: Length varies (select size); Height 3.5", Width 11.25"