Typical Emission Label on Leaf blowers

In order to simplify the ability to determine emission compliance in the field by an enforcement agent for a city, only the manufacturing date is important.  The reason the date January 2005 is so important is because that was the date when Class IV was implemented at its lowest allowable level. This class is the most popular engine size in use today on leaf blower.  

So, in order to learn when a unit was built, on older units, one need only look for a code or date that indicates when the unit was build.  For older units the code is represented from A through L for January to December with the following two digits indicate the year (Example: A05 = January 2005).  On newer labels, the date of manufacture is clearly spelled out.