Ohh I see! How many is the usual amount or how many would u use?
A standard 60% keyboard will use a total of 5 stabilisers - four 2U and one 6.25u. It's used with the space bar, two shift keys, your enter/return and the backspace.
Keys with extra holes will utilise stabilisers. The image below shows the common sizes:
How many you would use is dependent on your layout of choice and up to you, ones preference. It can be none at all to your general set of 8 on a full-size standard keyboard or more stabilisers as you peak into custom builds on your keyboard adventures.