MJL Regular Mouth Half Pint Silicone Sleeve for Mason Jars (Bright Blue) Fits *Regular Mouth* Half Pint Jars - Check the pictures if you aren't sure what size jar you have. RM 8oz Mason and jelly jars have straight sides and are 2 3/8" internal diameter. Prevent Breakage - We use glass jars instead of plastic cups for our kids' beverages, and the sleeve helps protect them from breaking when they inevitably hit the ground. Twice as thick as competing brands, for much better insulation and drop protection. Protect Your Hand From Hot and Cold - Perfect for heating up food or beverages in the microwave. No cut out areas that leave your fingers unprotected. Does not absorb condensation. Multi Purpose - Coffee, cocktails, and soup are all tastier from a Mason jar. Add a drinking lid, or stainless steel lid & straw, to make a plastic free travel mug. Or add a leak proof lid and bring lunch to work or school. Food Grade Silicone Rubber - Dishwasher, freezer, and microwave safe. Silicone is a safe, BPA-free material for food use that does not leach any chemicals.