1st impression when you hold this attachment in your hand: "not much to it", Kreg sure is makin' $$ here.
Then I installed it.. perfect fit, leaves just enough room to adjust the setting screw on my K4.
Then the real test, hook up the "shop vac" and start drilling.. I was amazed virtually NO SAWDUST escaped.. this contraption is well worth the "price of admission"
Lesson.. when removing the drill from the "jig", withdraw it slowly while still spinning,. In my experience, this results in NO sawdust escaping.