A flow meter comprising: a housing and a flow channel arranged inside the housing; two ultrasonic transducers (4, 5) disposed along the flow channel and arranged at a distance from one another, wherein the first ultrasonic transducer is configured to emit an ultrasonic signal into the flow channel and the second ultrasonic transducer is configured to receive the ultrasonic signal emitted by the first ultrasonic transducer; three reflectors (6a, 6b, 6c) arranged inside the flow channel, the three reflectors (6a, 6b, 6c) being configured to reflect the ultrasonic signal emitted by the first ultrasonic transducer multiple times on its way to the second ultrasonic transducer such that a W-shaped path of the ultrasonic signal is formed; wherein the flow channel is formed by a tubular member inside the housing; wherein the tubular member comprises a wall having an inner surface, the reflectors (6a, 6b, 6c) being arranged on the inner surface of the wall; wherein the flow channel comprises a flow restriction member, the flow restriction member being interposed between two out of the three reflectors (6a, 6b, 6c); wherein the flow restriction member comprises a first wedge (16b, 16c) having a first sloped surface; wherein the first wedge (16b, 16c) comprises a first plurality of teeth (17c - 17e) protruding from the first sloped surface, wherein the flow channel comprises an outlet port; wherein the flow channel comprises an inlet port, the inlet port being arranged opposite the outlet port and a fluid path extending from the inlet port to the outlet port; wherein the three reflectors (6a, 6b, 6c) comprise a first reflector, the first reflector being disposed closest to the outlet port amongst the three reflectors (6a, 6b, 6c); wherein the three reflectors (6a, 6b, 6c) comprise a second reflector, the second reflector being disposed closest to the inlet port amongst the three reflectors (6a, 6b, 6c); wherein the flow restriction member is interposed between the first reflector and the second reflector; wherein the flow channel comprises a fourth wedge having a fourth sloped surface; wherein the fourth wedge comprises at least one tooth (17a - 17b) protruding from the fourth sloped surface; and wherein the fourth wedge is disposed between the second reflector and the inlet port. a housing and a flow channel arranged inside the housing; two ultrasonic transducers (4, 5) disposed along the flow channel and arranged at a distance from one another, wherein the first ultrasonic transducer is configured to emit an ultrasonic signal into the flow channel and the second ultrasonic transducer is configured to receive the ultrasonic signal emitted by the first ultrasonic transducer; three reflectors (6a, 6b, 6c) arranged inside the flow channel, the three reflectors (6a, 6b, 6c) being configured to reflect the ultrasonic signal emitted by the first ultrasonic transducer multiple times on its way to the second ultrasonic transducer such that a W-shaped path of the ultrasonic signal is formed; wherein the flow channel is formed by a tubular member inside the housing; wherein the tubular member comprises a wall having an inner surface, the reflectors (6a, 6b, 6c) being arranged on the inner surface of the wall; wherein the flow channel comprises a flow restriction member, the flow restriction member being interposed between two out of the three reflectors (6a, 6b, 6c); wherein the flow restriction member comprises a first wedge (16b, 16c) having a first sloped surface; wherein the first wedge (16b, 16c) comprises a first plurality of teeth (17c - 17e) protruding from the first sloped surface, wherein the flow channel comprises an outlet port; wherein the flow channel comprises an inlet port, the inlet port being arranged opposite the outlet port and a fluid path extending from the inlet port to the outlet port; wherein the three reflectors (6a, 6b, 6c) comprise a first reflector, the first reflector being disposed closest to the outlet port amongst the three reflectors (6a, 6b, 6c); wherein the three reflectors (6a, 6b, 6c) comprise a second reflector, the second reflector being disposed closest to the inlet port amongst the three reflectors (6a, 6b, 6c); wherein the flow restriction member is interposed between the first reflector and the second reflector; wherein the flow channel comprises a fourth wedge having a fourth sloped surface; wherein the fourth wedge comprises at least one tooth (17a - 17b) protruding from the fourth sloped surface; and wherein the fourth wedge is disposed between the second reflector and the inlet port.