The HMIYUPSKT11 is a battery backup unit from Schneider Electric's Harmony iPC range — an Uninterruptible Power Supply Kit that includes the UPS battery and a 3-meter cable. It's designed to keep an industrial PC running through a brief power dip or allow a controlled shutdown when the mains drops out.
This is an electrical accessory — a battery backup specifically for the Harmony iPC family of industrial panel PCs. It's not a generic UPS; the cable length and connector are matched to the iPC's internal power input, so it mounts inside the panel or clips onto the PC chassis. If you're maintaining a line with Harmony iPC units and the original battery backup has failed or was never installed, this is the part that keeps the HMI alive through a 3-second brownout.