A system for indicating the pressure in an aircraft landing gear shock absorber is provided, the system comprising a source of collimated light and a target, the source of collimated light being attached to the aircraft, and being operable to emit light onto the target; the position of the point of incidence of the light emitted from the source of collimated light on the target being indicative of the pressure in the aircraft landing gear shock absorber. A kit for making such a system and a method of indicating the pressure in an aircraft landing gear are also provided.