Never understood the recent popularity of these types of sink. They're known as 'undermount sinks', and when poorly fitted they leave a gap which acts as a dirt trap between the sink and the worktop. There's also the problem of how to prevent water from damaging the worktop where it sits on the top edge of the sink. Anyone thinking of fitting one should consider a ceramic 'inset' kitchen sink instead. They look much the same, but incorporate a lip that sits on the worktop, meaning there's nowhere for the dirt to become trapped, and no risk of water damage to the worktop.