I know on the VEX site, there are two different tie straps available. 4" (18 pounds) and 11" (30 pounds).
There are many teams that purchase their own tie straps from home depot or walmart due to cost. How important is it for teams to find exact equivalent tie straps? How do the inspectors tell if they are equivalent? Is it just by size (length and thickness)?
So, by this rule it is very important for teams to find identical “tie straps”. Both length and thickness are the main criteria that the inspectors will be looking at. Please note that it is acceptable to use “tie straps” of a different color.
Ultimately, the final decision on whether or not any part is identical to one sold on VEXrobotics.com is up to the discretion of your inspector.