The special shoulder with ribs gives just the right separation between cups - when seated one on top of the other they simply don't "stick" ― one cup can be picked up off another leaving that cup behind; one cup can be dropped out of a set of cups from the bottom simply by releasing the finger holding it.

The reinforced lip of the cup is just the right size, not too pronounced, with a smooth, clean finish.

The 3 holes in the top are very important to fastest stacking ― these holes allow the air to escape quickly when downstacking.

Speed Stacks have "memory" ― if a single cup is accidentally squeezed at the lip it will bounce back into its round shape.

The inside surface of a Speed Stack is smooth for less friction.

The outside surface of each speed stack cup has been textured for a terrific feel and grip.