I use this adapter to help inflate camping mattresses, it fits inside a Big Agnes® Pumphouse* and makes it easier to attach and remove the pump. Valve sizes vary so the scale will need to be adjusted to match the particular valve you use.
The adapter in the picture is printed in NinjaFlex, but I've used a nylon version in the past (it works better with flexible plastics). The NinjaFlex version of model is slightly narrower to take into account the elasticity.
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