... and gently massage. Certification MSDS, CE, SGS, FDA, ISO13485 Gel PVC Slipperhelp stimulate blood circulation can relax and gently massage ... , FDA, ISO13485...Also known as: cold hot pack, gel pad, gel pack, compress pack, microwavable hot cold pack, etc. MaterialPVC, PE+PA or ... around 3 minutes; for cold use, please place it in the freezer for half and hour before using gel slipper, cold gel pack,