A reservoir and a plunger head contained within may be configured to move relative to each other in response to at least one of the reservoir being detached from a base, the base and/or the reservoir being removed from a packaging, and the base and/or the reservoir being moved relative to each other. A first layer may be configured to define a reservoir, the first layer, which may be made of a material compatible with fluidic media in the reservoir, may be adjacent a second layer for inhibiting a diffusion through the second layer. A first layer that may be less than 0.3 mm and made of a cyclic olefin copolymer may be configured to define a reservoir. A reservoir may be defined by a wall made of a cyclic olefin copolymer and the wall may be for substantially preventing light from passing through the reservoir.