The setup includes:
(2) Model 616 Round Halogen Lamps
(2) Steel seat brackets 
(2) Standard mounting bail brackets
(1) Steel cross mount with (2) nuts and bolts
Lamps measure 5-5/8"
Available in any color combo of your choice. 
All components are new old stock
This kit will work with a variety of vehicles. This mounts directly to the existing seat bolts on your vehicle. 
This setup was widely used in California in the 70s, 80s, & 90s mounted in the rear deck on the driverside. Many other California agencies also used this setup in a variety of color combos. 
Requires a flasher to alternate flash if desired. Not included.