The opening of a shredder can affect its capacity, because if it is small, you will need to fold the paper to fit it into the machine.
If you are looking for a shredder for a home office or business you may want to purchase a larger model that can handle the higher volume generated from invoices and client information.
Disintegrator shredders provide the highest level of security since the paper is reduced to tiny pieces or even powder, but they are very expensive for home use and are not usually necessary for household security.