They fit any 3.5" aftermarket speaker.
They include 4 standoffs that you can use or NOT use depending on your speakers. The standoffs go under speaker tabs and are just held in by the pressure of the screws holding the speakers in.
You will need to use screws to secure it into dash. Holes are already in the adapter just zap in some screws and you are good to go.
Screws go in so it wont show with the adapter in or if you want to put factory back in because they go into the lower flange not the actual dash.
On 3.5" speaker with huge magnets like the SKAR 3.5" ,you will need to trim the corners of the stock speaker mounting tabs so the magnet has clearance. But most normal 3.5" you wont need to trim anything.