These 1/4-20 stud packs contain equal counts of each of the 7 threaded studs available as individual pieces. Packs are available as a convenience so you don't have to order each one multiple times. If you want all of them, order a pack of the count you want.
Each pack# refers to the count of each stud in the pack. A 4-pack will have 4 each of all 7 studs.
Get a full pack to have on-hand when you need to make T-Bolts or custom-length knobs.