The Roller Derby Viper M-1 women's quad speed skates are great for beginners and intermediate skaters. Crafted around an RTX Pro chassis they feature a speed profile boot with a reinforced support a padded collar for comfort and a VELCRO brand closure power strap. The 58mm wheels ride on ABEC 5 bearings with a Mag core.The Roller Derby Viper M-1 women's quad speed skates are great for beginners and intermediate skaters. Crafted around an RTX Pro chassis they feature a speed profile boot with a reinforced support a padded collar for comfort and a VELCRO brand closure power strap. The 58mm wheels ride on ABEC 5 bearings with a Mag core.