Do I need to buy a socket or tool to install these?

You'll need a standard lug nut socket that fits M12 hardware — most common wheel shops and home garages already have one. Check your socket set before ordering if you're unsure of the size.

Will these work if I'm running wheel spacers?

That's exactly why the 60mm extended length exists. They're designed to clear spacers without forcing you into adaptors or shorter nuts that won't seat properly.

What makes the four locking nuts different from the rest?

The locking nuts have an internal feature that grips the stud to resist vibration loosening. Install one on each wheel for maximum security, especially if you're on the track or dealing with rough roads.