Weighs only 50g. Constructed from the most lightweight and comfortable material. It is reusable material that’s washable. It’s thermal insulating properties allows it to retain heat of cold beverages in plastic cups. Just that tad more coolness in the hot summerr and extends thermal values by over 80%. A cup of 80d hot beverage that’d take 30 minutes to naturally cool to room temperature will take 3 hours instead in this thermal sleeve.