Which attachments will fit my Chef?

This would greatly depend on which model of Chef you have. The model number is located on the underside of the Chef.
The below is a brief overview of which attachments are compatible with which models:-

A701: Only compatible with attachments starting with A7*
A901: Compatible with attachments starting with A9 or AT*
KM models: Compatible with attachments starting with AT*

If using a KAT100ME adaptor, slow speed attachments starting with KAX can be used KVL models:

Compatible with attachments starting with KAX/KAH/KAB/KAT*

If using a KAT200ME adaptor, slow speed attachments starting with AT can be used

KVC models: Compatible with attachments starting with KAX/KAH/KAB/KAT*

If using a KAT200ME adaptor, slow speed attachments starting with AT can be used

*Food Processors Attachments:

The KAH647PL Food Processor will only operate on a high speed outlet

The AT640/AT647 Food Processor will only operate on a medium speed outlet

More information on the attachments available can be found by clicking this link .