The Sanwa OBSF-30 button is widely used in Japanese cabinets such as Astro City. They feature a slightly convex plunger and snap-in installation and can be mounted into a panel that is 2mm to 5 mm thick.
Each button contains a “non-clicking” microswitch which makes it very smooth and extremely quiet. With its fast response and short throw the OBSF-30 is regarded as one of the best competition pushbuttons on the market, especially by devotees of fighting games such as Street Fighter.
These pushbuttons require a 30mm diameter hole and will mount in a panel between 2mm and 5mm thick. If you plan to use them in a panel thicker than this either the panel or the pushbutton(s) will need some modification. Please ensure that you consider this before ordering.