Take an old lens and go to an RV shop or Automotive retail shop. They have SAE numbers stamped on the lens and usual the manufacturer.
2014 Ram 1500 CrewCab 4x4 5.7 Hemi 3.92 Rear and Air Lift 1000
2005 Jayco Jay Feather LGT - 29Y GVWR-7000 lbs.
Dexter Axle Lift 4-9/16" - installed with sub-frame.
Pro Series 1200 lbs. WDH with Double Sway Bar.
Champion 3100/2800 watt Inverter/Generator-Onboard Solar Power