Christopher's equipment (3)
I believe the answer is:
kit
This clue is a double definition.
'christopher's' is the first definition.
(short for Christopher)
'equipment' is the second definition.
(I know that kit is a type of cogwheel)
(Other definitions for kit that I've seen before include "Equipment; young ferret" , "Set of articles or tools" , "tackle" , "Young beaver" , "Equipment, clothing" .)