Maybe one of these similar products would be of interest:-
Z1R Z1R Helmet Bag - Black 3514-0007 YAMAHA HAONDA KAWASAKI SUZUKI KTM BMW
Speed & Strength SS2210 Cool-Core Helmet Liner, Large NA Liner 87-6990
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Motorcycle Helmet Liner Silicone Pad Breathable Cycling Helmet Snow Type Liner