Yes, you can change the attenuated filters. We stock a range of filters with different levels of decibel protection, you can order filters here
We have supplied your SnugsGo Shield with Dynamic Ear Corps (DEC) attenuated filter. These are the best all filters available being small and water-proof. If you need more or less attenuation then you can easily change the filters.
The 26 NRR (33 SNR) certification is with a solid block filter.