PAC BB-2PR Pair of Bass Blocker Designed for 6" Speakers, Green

Does this crossover work only with 6" and 6 1/2" speakers (as said)? what does the speaker size have to do with blocking certain frequencies?

Can these handle 100watts ? I have a separate sub , so I want only light mids and highs for my door speakers

Could I use theses with jl c2-350x speakers on a jk with a jl amp and kenwood headunit?

Does anyone know if there is a rated power these can handle, im thinking of using these on an amplifier that has about 250 watts @ 4 ohms, bass wise