The Oyster 4 Tandem Adaptors convert your Oyster 4 single pushchair into a tandem pushchair making it suitable for twins or toddler and baby siblings. The Oyster 4 Tandem Adaptors offers 8 approved configurations for your Oyster 4, including: Oyster 4 Seat Unit & Oyster 4 Tandem Seat – max. 15kg per seat (wheel guards must be used when a seat is in the bottom configuration), Two Oyster Carrycots – max. 9kg per carrycot, Two Oyster Capsule Infant Car Seats, Oyster Capsule Car Seat & Oyster Carrycot, Oyster 4 Seat Unit & Oyster Carrycot. Using the Oyster 4 Tandem Adaptors, the Oyster Basket allows the stroller to be a true family companion, suitable for pets (or shopping) up to 9kg in 3 approved configurations. Features: Compatible with the Oyster 4 stroller Converts a single stroller into a tandem Quick and easy to install