I bought an Alpinestars Nucleon KR-21 Level 2 Back Protector Insert last August for £29-99. Better than the piece of foam that came with the Alpinestars jacket !
Forcefield ones are thicker than standard ones (which one would assume is better for protection) so if your jacket is already tight fitting take that into consideration as it'll be even tighter! Sent from my E6653 using Tapatalk