Compatible Dyson DC07 tool set includes crevice, stair and brush tool

When would this part need replacing?
When the tools are split/broken
When the tools are missing

Will fit DC07 models below:

DC07 Standard, DC07 All Floors, DC07 Allergy, DC07 Animal, DC07 CLIC, DC07 Full Gear, DC07 Full kit, DC07i grey/red, DC07 Origin, DC07 Tool kit, DC07 HEPA, DC07 Precision, DC07i

Compatible Dyson DC07 tool kit