This adapter lets you convert a European-style DIN battery vent hole to the standard quarter-turn bayonet style. This includes some batteries made by Douglas Battery Co. The adapter fits into a 1-3/8″ vent hole. As a result, it lets you install any quarter-turn style bayonet vent cap. The O-ring seal is included. The part drawing can be viewed online to see the dimensions.
Also, we make more adapters that can be viewed by choosing one of these links.
#4D-8D-PIA Battery Vent Adapter
#4D-8D-SIA Battery Vent Adapter
#M27x3-SIA Battery Vent Adapter
#M22X1.5 Battery Vent Adapter