The Bio Shield disposers are designed to fit sinks with a 90mm sink hole. If the sink hole is not this size, it is a simple matter to connect your disposer by use of one of the following methods:
1.   Stainless steel, ceramic or marble sink holes can be enlarged by using either a hole punch tool or a hole saw.

2.   Porcelain sinks can be fitted with a 60mm adapter that is available to replace the current mounting assembly on the Bio Shield disposer.