A flow meter device comprising: a liquid inlet; a liquid outlet; an inlet passage that has an upper and a lower end and that is in communication at its upper end with the liquid inlet; an indicating chamber having a lower end that is in communication with the lower end of the inlet passage, the indicating chamber extending upwardly from its lower end to an open upper end, wherein at least part of the indicating chamber is translucent or transparent to show the height of liquid in the indicating chamber; an exit chamber that is in communication with the liquid outlet; and a flow-resistant liquid passage extending between the lower end of the inlet passage and the exit chamber and in communication with the indicating chamber; wherein the flow-resistant liquid passage provides greater resistance to liquid flow than both the inlet passage and the indicating chamber, whereby liquid can flow from the liquid inlet through the inlet passage and through the flow-resistant liquid passage into the exit chamber and from there to the liquid outlet and also from the inlet passage into the indicating chamber where it reaches a height that is in accordance with the flow of the liquid through the inlet passage; characterized in that: the device is made in two parts, a first part including the liquid outlet and the exit chamber and the second part including the liquid inlet and the inlet passage and wherein the flow-resistant liquid passage and the indicating chamber are provided between the first part and the second part; and the flow-resistant liquid passage is U-shaped and wherein the first part includes a closed bore and the second part includes a barrier located in the bore to divide the bore into separate channels that together form the U-shaped flow-resistant liquid passage. a liquid inlet; a liquid outlet; an inlet passage that has an upper and a lower end and that is in communication at its upper end with the liquid inlet; an indicating chamber having a lower end that is in communication with the lower end of the inlet passage, the indicating chamber extending upwardly from its lower end to an open upper end, wherein at least part of the indicating chamber is translucent or transparent to show the height of liquid in the indicating chamber; an exit chamber that is in communication with the liquid outlet; and a flow-resistant liquid passage extending between the lower end of the inlet passage and the exit chamber and in communication with the indicating chamber; wherein the flow-resistant liquid passage provides greater resistance to liquid flow than both the inlet passage and the indicating chamber, whereby liquid can flow from the liquid inlet through the inlet passage and through the flow-resistant liquid passage into the exit chamber and from there to the liquid outlet and also from the inlet passage into the indicating chamber where it reaches a height that is in accordance with the flow of the liquid through the inlet passage; characterized in that: the device is made in two parts, a first part including the liquid outlet and the exit chamber and the second part including the liquid inlet and the inlet passage and wherein the flow-resistant liquid passage and the indicating chamber are provided between the first part and the second part; and the flow-resistant liquid passage is U-shaped and wherein the first part includes a closed bore and the second part includes a barrier located in the bore to divide the bore into separate channels that together form the U-shaped flow-resistant liquid passage. the device is made in two parts, a first part including the liquid outlet and the exit chamber and the second part including the liquid inlet and the inlet passage and wherein the flow-resistant liquid passage and the indicating chamber are provided between the first part and the second part; and the flow-resistant liquid passage is U-shaped and wherein the first part includes a closed bore and the second part includes a barrier located in the bore to divide the bore into separate channels that together form the U-shaped flow-resistant liquid passage.