I got sick of using my "Common" funnel for different uses, trying to clean up an oily funnel so you can use it for Sea Foam is just dumb when you can get these for a little more than $1.  The size/length is perfect for gas-tank additives.  I purchased 3, I keep one in the garage to pour Sea Foam into my cara/motorcycle/snow-blower/lawnmower.  And the other 2 I keep in whatever vehicle I'm currently using, in my "just in case" pack.