I'm looking to get a sun flap that will cover the back of my neck and ears and will work with my ball cap. Any recommendations out there? Thanks

Cool towels work pretty good. They come in different sizes. Dunk in water wrap around the Neck. Not sure on how much ear protection.

I purchased a Foreign Legion style olive drab cap at an Army-Navy store a while back. Another option would be to modify a regular ball cap. Could be done with Velcro and any style cloth or cooling cloth and the Velcro would allow you to remove the cloth and wash it.

https://www.amazon.com/dp/B07SZ3G1T4/ref=sspa_dk_detail_0?psc=1&pd_rd_i=B07SZ3G1T4&pd_rd_w=ePZ0X&pf_rd_p=48d372c1-f7e1-4b8b-9d02-4bd86f5158c5&pd_rd_wg=DG6XT&pf_rd_r=ANHCB2JBRXNSDRZ0T3A7&pd_rd_r=b0c649a7-d268-4c2e-89cb-3016180bc37f&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzTVI1Sjk4QlJJOEdNJmVuY3J5cHRlZElkPUEwMzg1MTI1M1RSVEw5NEo2WElIVSZlbmNyeXB0ZWRBZElkPUEwNjkwMDQzNDM4NVNENjJGUkJDJndpZGdldE5hbWU9c3BfZGV0YWlsJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

Look on Amazon for "sun flap for ball caps"