IMG 8862 Coolermaster Cosmos 1000 Chassis

The sidepanels are secured by this latch,

IMG 8861 Coolermaster Cosmos 1000 Chassis

and you can release the side panel just by pushing the latch upwards.

IMG 8863 Coolermaster Cosmos 1000 Chassis

and the side panel comes off!

IMG 8865 Coolermaster Cosmos 1000 Chassis

The side panel comprises of mainly aluminum, reinforced with a layer of steel, and the black stuff you see is a layer of noise insulation material added to dampen any possible noise generated by any mechanical components within the case.

IMG 8870 Coolermaster Cosmos 1000 Chassis

Side view with the side panel removed. The black duct that you see in the middle of the case is used to channel airflow to the expansion cards within the case.