Method and arrangement in a base station, a user equipment and a positioning node, for sending, and obtaining, respectively, a value of a propagation delay of a signal. A fluid channel passes through the bushing, wrench collar, and base plate, and a one-way valve is disposed within the fluid channel. A first portion of the fin structure is a first doped portion that is disposed over a first recess in the surface of the insulating layer and a second portion of the fin structure is a second doped portion disposed over a second recess in the surface of the insulating layer. The possibility of the free game bonus round occurring at any time provides incentive for players to keep playing the linked gaming machines.