Sorry if this question has been asked before. For the last couple days I've been doing some digging online and can't seem to find an answer to my question:

Is Ortho Weed-b-Gon Max with Grabcrass Control a pre-emergent? (Product Link)

I talked to people at Lowe's and The Home Depot - they both told me yes. However I am a little skeptic since they're not always lawn experts... and both seemed unsure of their answer... so I was thinking a simple search online would answer this. But I was wrong, everything talks about spraying it, when to spray it (early spring as the weather warms, which signifies to me pre-emergent) but nothing specifically says it IS.

Any help is appreciated!