CAOS
Alpha Architect Tail Risk ETF
stockBATSETF

Great suggestion on percentage amount needed for any benefit and dbmf has been a great addition for me. It moves up slowly as things move down, and it does spike up if things go real bad. Gives dry powder by selling to buy other stocks/etf during a drop. Pays a div quarterly and gives a much bigger div in December. I also use CAOS etf in case of catastrophic drop. Tflo is my cash safety/bond type and also use Jaaa for higher return.