This is the GW 31-74 Horus Heresy: Solar Auxilia Tactical Command Section plastic kit

This multipart plastic kit builds a Solar Auxilia Tactical Command Section, comprising one Auxilia Captain and four Auxilia Companions. These soldiers are clad in finely decorated void armour, and carry command gear alongside their lasrifles – the kit includes an augury scanner, a command vox, and a proud cohorts vexilla, as well as a lethal melta bomb. The Captain comes with a choice of heads, and loads of extra weaponry – a power fist, power sword, or charnabal sword, as well as a laspistol, blast pistol, needle pistol, plasma pistol, or hand flamer.

This highly versatile kit can alternatively build a lower-ranking Line Command Section, wearing less ornate armour and carrying a more austere vexilla. It can also be used to build a Legate Marshal, accompanied by four Lifewards. You'll find even more weapons for the Legate Marshal – a volkite serpenta, inferno pistol, or archeotech pistol, and a thunder hammer or paragon blade – and the Lifewards can be armed with some of their lord's spare wargear!

This kit comprises 137 plastic components, 5x Citadel 25mm Round Bases, and a Solar Auxilia Infantry Transfer Sheet containing 152 high-quality waterslide transfers. These miniatures are supplied unpainted and require assembly

Note that this kit includes enough components to build an additional Auxilia Companion, if you have a spare Citadel 25mm Round Base.