An SWE6 Multifunction I/O module and an Optical Pulse Sensor at a reduced price over buying the two items separately.
These two products work very well together allowing you to use your 1-Wire network to monitor any electricity or other utility meter that has a flashing LED indicating your consumption.
The Pulse Sensor plugs straight into CN4 and uses the counter input on the SWE6, the other four I/O pins remain available for other uses.
Please see the individual products pages for more details on each item.