Hexagonal shaped jet with IG stamped on the side for gasoline (petrol if you are a Brit), for the pre-2012 MSR WhisperLite International stove.
Part Number: 419607.
This stove has wire legs and comes with a K Jet. If it didn't include the K Jet when you bought it then it is probably not an International so the G Jet that you need is not this one, it is 419425.
Shaker Needle not included.