Roller Derby have updated the popular Viper to the M4. This new Retro style low cut skate is ideal for beginner & intermediate skaters of all ages. The Viper Speed RTX Frame with Action Control System ensures you experience the maximum control for this new skate. This boot is also a preferred skate for the Roller Derby Sport. Features: Deluxe Speed Profile Boot with Comfort Padding and Reinforced Support Full Lace System Closure with Velcro Power Strap RTX Pro Series Frame 58mm x 40mm MAG Core Urethane Wheels Abec 5 Bearings FIT We recommend you order your normal shoe.