Recommended UPS for Vigor 2865ax

I was considering a UPS unit for my Draytek Vigor 2865ax, rather than one that provides a main socket I saw some models that connect directly to the DC port, does anyone have any recommendations of UPS models?

TIA

I use a Schneider APC Back-UPS connect about £56 form Amazon it gives about 3-4hrs of use when the mains is off.