not the same as Vactrol
Although these are purported to be like the old Perkin-Elmer Vactrol devices, they do not meet the same ON state resistance as the originals. The original VTL5C1 routinely had an ON resistance of around 200 ohm or less at about 40 ma. current (Max rating). The Xvive version typically exhibits 600-800 ohms at that draw. If your application is critical to the ON resistance, be aware that these will not perform the same.