The Siemens 3VA9483-0JA13 is a SENTRON box terminal designated TS1.5, sold as a three-unit pack. It's an accessory designed for the 3VA1 and 3VA2 molded-case circuit breaker families in the 400 A and 630 A frame sizes. The busbar slot accommodates a maximum of 2 bars sized 10x24 mm x 1 mm and a minimum of 2 bars sized 10x20 mm x 1 mm. That tells you the physical envelope for the busbar you're feeding through — the 24 mm height gives headroom for a taller bar, but the 1 mm thickness is fixed regardless of width.
Panel fit and sourcing
This is a line-side or load-side lug kit for 3VA breakers — you swap the factory terminal for this box-style when you need to land large aluminum or copper conductors. The TS1.5 designation means it's the smaller of the box terminal options for the 400/630 A frame; there's a larger variant for the 800 A and up frames.