The 2nd board kit is everything you need to mount a second board and not have to worry about stance width everytime. Comes with 2 disks of your choice,e-rings of your choice, center disks of your choice, and the hardware to mount everything.

Not chosing a center disk will default the shipment to 4 hole.

3 HOLE center disks are only necessary if you have a Burton Snowboard! Evey other Snowboard uses a 4 hole pattern.