The cause of poor loading performance from the Atari 410 Cassette unit is often a perishing drive belt becoming slack, or more commonly kinked where it has sat without moving around the drive pulley for 30 years or so. This kink then becomes a permanent feature of the belt causing it to jump and slip.
These belts are as close as possible to the design and size to the originals but made from modern, more resilient materials.
