3PMSF Tires
From Free Knowledge Base- The DUCK Project: information for everyone
Three-Peak Mountain Snowflake tires or 3PMSF tires are those that utilize a rubber compound that retains flexibility and traction in cold temperatures.
The 3PMSF symbol or icon, which appears as a snowflake inside the outline of a three-peaked mountain, often sits next to the letters M+S (Mud and Snow rated) on a tire’s sidewall. While not every all-season tire is designed for severe winter driving conditions, the 3PMSF designation found on some of them means you will have more grip than a standard all-season tire.