Linear s hardened crown rollers are a superb choice for low, Cost linear motion. The rollers come pre, Assembled and are self, Aligning for simple installation. Hardened crown rollers are great for point, To, Sturdy and ensure, And long strong, Point applications, Lasting linear motion. Hardened crown rollers are a leading example of the least expensive bearing systems. Note rails, Wheels, End stops, And angle brackets must be ordered as individual items below. Maximum wheel bearing load up to 1334 n 300 lbs maximum transfer speed up to 762 mm/s 30 in/s rails available up to 3 m 10 ft in steel or Durable powder finish integral roller bearing with metric or inch threaded stud available angle mounting brackets & rail end stops ideal for machine tool doors and guarding ideal for point to point material transfer ideal for doors and windows garage doors ideal for a variety of additional general purpose applications