A cellular network configuration tool is described that performs frequency assignments for use in a cellular network. Also a wheel including a hubcap and a clamp. The passages are adapted in regard to size; distribution; or size and distribution to a fluidic configuration of the filter element such that non-uniform fluid flows that exist in operation of the filter element upstream of the support tube are compensated. Consequently, the two connection faces 32, 62 come close together over the entire faces to give precise electric connection of the electric connection points between the two connection faces.