This is a posable action figure from the Nendoroid series.
From the Good Smile Company website:
From "Star Wars Episode 4: A New Hope" comes a Nendoroid of Darth Vader! His jet black outfit has been faithfully shrunk down to Nendoroid size, with a mix of glossy and matte paintwork to bring out the different textures. His lightsaber is included and the blade can be attached and removed for various posing options. He also comes with parts to hold the lightsaber in both hands, or a single hand.
Two different cape parts are included - one with a fixed pose that has a solid appearance, and another that is articulated for more dynamic poses! A Death Star is also included allowing for even more fun! Just looking at the Nendoroid and Death Star is sure to get The Imperial March playing through your head!