Here you go. I got a c4 and use this on my ups.
TENINYU USB 2.0 A Male to DC 5.5x2.1mm 5 Volt DC Connector Charge Barrel Jack Power Cable Black, 3FT (Max 2.5 Ampere Power Cable, Center PIN Positive) https://www.amazon.ca/dp/B01N7RL57X/ref=cm_sw_r_cp_apip_uEnfixNvyCyuj
