I don't currently use a vape bag. When I leave the house, I usually carry a couple of single battery regulated setups that can fit easily in a pants or coat pocket. Maybe a couple of spare 18650 batteries in a plastic battery case. Maybe a 30 ml bottle of juice. (Maybe I do need a small vape bag.

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A few years ago I used to work in a vape shop. I found it sometimes useful to have my different mods and juice attachments with me (up to a dozen) to show customers how they looked, felt, and worked. At that time I transported my setups in a mini-laptop bag that I found on clearance. If I go out of town for a weekend I may bring a couple mods, bottles of juice, batteries, and charger in the bag.