This product is a Pillow Paws XXL slip resistant Risk Alert (Explanation From MFG In Last Paragraph) hospital sock. These socks can also be worn at home to keep elderly or anybody who is in danger of slipping or falling out of harms way. They have ink on the bottom which puffs up and grips to the floor to make it harder to fall. Everything from here on is words from the MFG. Single-Imprint Terries Slipper Socks provide warmth, comfort and peace of mind with a very strong and patented grip on the bottom of the sock. This listing is for Double Tread so no matter which way you put on the sock the socks grip will still touch the floor. Words From The Manufacturer - The quality and comfort of our Pillow Paws terry knit socks make them the most wearable patient footwear products in the industry. Unlike other manufacturers, the slip-resistant tread is printed on the smooth side of the terrycloth fabric. This allows the ink to “puff” and create a full, robust tread design. The ink is not lost in the terry loops, enhancing safety and comfort. Our Pillow Paws Terries Slipper Socks are machine washable for multiple usages. Pillow Paws Risk Alert Terries Slipper Socks follow the “Arizona Standard” for color-coding patients to condition. The color purple informs caregivers the patient does not wish to be resuscitated. It is important for caregiver to check the patient’s chart and adhere to the patients wishes.