Product review (2 stars): difficult to install
I have two sets of smoothtop burners in the house.  Both have a metal border/frame around the glass that supports them in the counter hole.  Installation of those was a simple drop in and secure against movement.

This model has bare glass edges with no support under the glass.  This requires mounting brackets to the cut counter edges.  Material must accept screws (not stone!).  Mounting is tricky since too high and weight will be on bare glass hitting bracket and too low will have glass supporting weight on counter.  Also need to be sure brackets not installed too far forward or back or screws to bracket will not hit unit.  Power cord, for some reason, comes out near front of the unit and is relatively short.  This means excessive exposure of power conduit to movement of items in any drawer just under the unit.  It would make much more sense for  wiring to travel within the unit and exit near rear like in the unit this one replaced.

The glass top without borders or frame is an attractive appearance, but leaves edges more exposed to chipping or cracking if something slides into cooktop from side.  Use of a metalic frame would allow better protection and a more tapered edge with better counter contact.  The bare glass edge is of necessity thicker and, being inflexible, leaves more of a gap at edges for debris to go under (plumbers caulk under or silicone caulk around edges is recommended to minimize this problem.