The Custom Molded Earplugs have a continuous noise reduction rating of 31. They are designed for consistent noise reduction across all decibel ranges.
The Percussive Filters are designed to block out loud percussive noises while still allowing ambient noise to pass through. Attached is a chart with the filter noise reduction rating so that you can see the different ratings at the different levels.
Both are great options, but dependent on the situation and use case. It will be up to your personal preference if you want specific protection against loud, sudden sounds or consistent hearing protection across all decibel ranges.
If you need consistent noise reduction, you will want the Custom Molded Earplugs.
If you need protection against loud sudden noises, while still hearing your surroundings, the Percussive Filters are the best option. However, if you intend to use at an Indoor Shooting Range, please double up on hearing protection or slowly enter the environment with the Percussive Filters properly in place to ensure they are working in that specific situation. Not all Indoor Ranges are the same.