#1 is the Comfort series for small-medium size eyeglass frames

#2 is the Circle series for medium-large size eyeglass frames

#3 is the Ministretch series for small-medium size eyeglass frames

#4 is the Primestretch series for large size eyeglass frames

#5 is the Superior series for medium-large size eyeglass frames

#6 is the Superstretch series for large size eyeglass frames

Also, in case you're interested, here are the unstretched and max stretched hole sizes for each of the styles in the Performance Pack:

2mm-6mm (0.0787"-0.2362") - Comfort series

3mm-7mm (0.1181"-0.2756") - Ministretch series

4mm-7mm (0.1575"-0.2756") - Circle series

4mm-8mm (0.1575"-0.3150") - Superior series

6mm-11mm (0.2362"-0.4331") - Primestretch series, Superstretch series