These items are designed to fit onto the 6-speed manual shifter in the Chevy SS (imported Holden Commodore sedan with C6 Corvette driveline). They include a boot lip to hold up your shift boot.
These shift knobs fit any SS with the stock shifter (or aftermarket shifter that fits the stock knob). The knobs attach using a sideways screw and the boot ring connects to the knob by sliding it upward and turning. No special tools are necessary.
The Shift Pattern Engraving will have this layout: