Best for: Reformer Pilates trainer socks that give you grip on the machines.. The features: These Trainer Grip Socks have grip spots on the sole so they don't slip on the machines in Reformer Pilates. In a 2-Pack.. Our fabric: Supersoft and breathable in a blend of bamboo and organic cotton. The recycled polyamide gives these socks durability and the stretch guarantees a comfy fit. The flexible grip spots are made from grippy bio Polytex which is 95% bio-based... 51% Bamboo Viscose, 34% Organic Cotton, 13% Recycled Polyamide, 2% Elastane. Elastane Grips spots on the sole. Easy care - wash at 30°