Product review (4 stars): Excellent Product!!, but accessories are needed.
You need the optional extension piece. (See HEARTLAND's website (heartlandnatural.com)). This piece is for outside your house only and will not adapt to a 4" PVC pipe w/out the (optional) extension that is listed as an accessory (it's a necessity).
That said, I don't know why they call it an optional accessory or an extension, you need it, or you can't connect to this vent and pipe it through your wall. They should just charge more and sell you everything that is needed. I would have given them 5 Starts if I didn't have to order the necessary extension separately.
I'll list my complete setup and you decide what is right for you... This worked for me, but you have to make sure you have all the info and all the right parts before  you start your project... So here they are...

Parts
1. HEARTLAND 21000 Dryer Vent Closure
2. HEARTLAND Extension accessory (Can be used as a 'through the wall' extension on the dryer vent.
7" in length.)
3. 4" Long 4" dia PVC
4. Dryer Dock Vent Hose Quick Connect
5. PVC Pipe Cement

Install
1. Pipe Cement the Dryer Vent to the Extension and allow the appropriate time to dry (do this in a well vented place)
2. Have someone hold the vent in place through the wall.
3. Slide the Quick connect into the PVC and slide the PVC over the 7" extension. You will have to cut down the 7" Extension so it will slide into the 4" PVC Pipe (coupler) without hitting the quick connect. you can decide these exact measurements during this retro fit. For me it was cut 2 " off of the 7" extension and cut " off of the 4" PVC
4. Screw in the Dryer vent
5. Slide on the 4"PVC with the quick connect
6. Screw in the quick connect

Done.

Luckily I had everything on hand because I bought the 4" PVC thinking it would connect to the vent and I figured I would need the PVC pipe cement (and I did). I had to cement the vent to the extension other than that everything else slid together tightly and screwed in nicely.
Hope this helps!