An inflow assembly for controlling fluid flow between a hydrocarbon reservoir and a production casing in a well, comprising a first tubular having an axial extension and at least one inlet and a first wall with at least a first axial channel extending in the first wall from the inlet, a second tubular having a first and a second end and at least one outlet, the second tubular being rotatable within the first tubular and having a second wall with at least a second axial channel extending in the second wall from the first end to the outlet. The assembly is configured to control a fluid flow between a hydrocarbon reservoir and a production casing in a well. The inflow assembly may also be utilized in a downhole completion comprising a casing string.