There are no mistakes, just happy little accidents. 
 
These rings are much bigger than anticipated however they still work just for their intended purpose for 25% of men. 
 
For BFR buy multiple packs (at least 3.)  
 
Most men over 5 inches base girth will be able use these for BFR clamping.  
 
The largest ring can roll over itself making it useful for average sized individuals.

NO COCK RING SHOULD BE WORN FOR LONGER THAN 40 MINUTES! 
 
BFR / CLAMPING SHOULD NOT BE DONE FOR MORE THAN 10 MINUTES PER SET!