Impressive new 4V Lithium Ion Capacitors. Compared to the Vinatech 3.8V 250F the Cda 4.0V 1100F and 350F are much cheaper 7.89 and 3.94 euro and have a much higher energy density. They have similar temperature range, leakage and ESR. https://www.aliexpress.com/item/1005007647013916.html