Winter Ball Cap Insert

I am curious if anyone knows of a product like this. I am wanting some type of wool insert to put in my ball caps for a little extra warmth in the winter months. I have seen cashmere caps and L.L. Bean makes a wool lined waxed cap.Here is the link for reference. https://www.llbean.com/llb/shop/516639?itemId=271100&attrValue_0=Khaki&sku=0KMM170000&pla1=0&qs=3155264&gclsrc=aw.ds&gad_source=1&gad_campaignid=20291392747&gbraid=0AAAAADoqq1Iq_ctCqekRvmFuiLkU6pKlh&gclid=Cj0KCQjwrJTGBhCbARIsANFBfgvGFZpH2R9wHr63m2XWtyS-uvknV5tp9Xz6C4NGVdNoMpB6kj2xIi0aAtl2EALw_wcB&SN=findability_search_preview_03&SS=A&SN2=findability_trending_searches_04&SS2=A&SN3=MobilePLA_03&SS3=B&noaa_region=ohiovalley&originalProduct=69287

I am wanting a wool insert that I could use in the hats I already own. Any suggestions on a product out there?