Calley is a small shunting engine and Dunbar's assistant. She has lots of different tasks to perform and plenty of service carriages to help complete each one. Calley is like a big sister to all of the young engines in Chuggington. Calley and the Box Car are compatible with the die cast playsets and tracks. This 2 piece pack includes a die cast Calley engine as well as a box car which can be attached using the front and rear couplings . Chuggington - Calley with Box Car 2 Pack is a fun way to encourage imaginative play.