This battery vent adapter was made to fit our #4000600 Battery Water Level Indicator on a Varta RL 840 battery (made by Enersys). But this adapter will fit any battery that has a vent hole with M27-3 threads. In addition, this adapter lets you fit all 1/4-turn bayonet-style vent caps on your battery.
Also, we make more adapters which can be viewed by choosing one of these links.
#4D-8D-PIA Battery Vent Adapter
#4D-8D-SIA Battery Vent Adapter
#1050VCA Battery Vent Adapter
#M22X1.5 Battery Vent Adapter