The Phil and Teds Classic Buggy Doubles Kit is a second seat attachment designed to adapt your inline stroller to meet the needs of your growing family. Attach this doubles kit to the front or back of your Phil and Teds Classic Buggy and convert your single stroller into a double stroller. The doubles kit features a 5-point safety harness, a padded, washable seat cover, and is meant for use from 6 months up to 4 years or the maximum load. The doubles kit can accommodate up to 44 pounds when attached to the front of the stroller, and 33 pounds when attached to the back.