Transfer switches move a load between power sources without dropping it: maintenance bypass switches that let a UPS be serviced or replaced while the equipment it protects stays up, and automatic transfer switches that shift equipment between two feeds when one fails. In any room where the UPS itself must someday be touched, the bypass switch is what makes that a non-event instead of an outage.
These are capacity-matched, wiring-matched purchases: the switch must carry the full load in kVA, match the UPS family and voltage it fronts, and be planned into the electrical path - a bypass added after the fact means downtime to install the thing that prevents downtime. Specify the transfer switch when the UPS is specified, not after. For racks, rack-mount automatic transfer switches give single-corded equipment a second feed without a rewire. COLAMCO quotes transfer and bypass switches with the UPS systems they support for business, government, and education facilities.