Add serious warmth and flotation assistance to your favorite uninsulated monosuit with the FXR F.A.S.T. Insulated Monosuit Liner. Designed for extreme cold conditions, it combines F.A.S.T. 3.0™ and Thermal Flex™ insulation for a total 210g insulation value and a maximum warmth rating of 9. Fully integrated F.A.S.T.™ technology adds flotation assistance for extra peace of mind when riding lake trails, river routes, and other areas near open water.

Moisture-wicking quick-dry mesh at the inner and outer body helps manage perspiration during active riding, while stretch gussets at the back shoulders and lower waist support natural movement beneath your outer shell. A quick-zip drop-seat function provides convenient access, while YKK® zippers throughout add dependable performance. Knit cuffs at the sleeves and lower legs help keep the liner securely positioned, and a soft fleece collar adds comfort around the neck.