MSR 419609 WhisperLite Shaker Jet K
Hexagonal shaped jet with K stamped on the side for kerosene/paraffin, for the pre-2012 MSR WhisperLite International stove.
The stove that this jet is meant for has wire legs and came with a K Jet. If it didn't include the K Jet when you bought it then it is probably not an International and cannot burn paraffin/kerosene.
Shaker Needle not included.