Genuine Miron: thick-bottomed, very high-quality glass that stays cold out of the fridge, so you can chuck it in a bag with your portable setup and you're basically good for the day. Smell proof even when lazily packed with the dankest of rosin, whereas vac packs fail the scent test straight off the production line.
Great for curing rosins in the fridge long term also; I just chuck these into larger glass jars to minimize condensation if I want to quickly pull a jar. Plastic top is unavoidable and offers the best seal. I'll never use mason jars again. [Thanks for shipping the small order!]