The JL / Gladiator Rail Mount dual Universals is explained by Gator Overland in this video.
Brad at TrailRecon explains why his wife selected the JL Rail for one of their first JL upgrades.
The JL Mount Rail video by Kevin shows the low profile design of the mount.
The JL Mount Driver Edition with MagMount is wonderfully explained by Lite Brite in this video.
The original JL Mount Driver Edition video by MYE Jeeps shows the low profile design of the single device mount.