Slim Straight Line Skates are based on the same design as our heavy duty long and short skates, utilizing rugged fabricated, fully welded steel frames that are manufactured from high quality North American steel in a narrow style. A single row of tandem rollers enables you to have heavy duty moving ability where space is limited . Capacities range from 2.5 Tons (5,000 lbs.) to 12.5 Tons (25,000 lbs.).