Instruction: Answer the given question by extracting information from the supporting document.

Input:
Question: I own nikon G lenses, 35 and 50mm, how do they work with this adapter on the GH4??
Document: On December 9, 2010 I bought a lens mount adapter Nikon G-M4/3 but instead I received a lens mount adapter Kiwi. The thing does not work, it is not what I ordered. I contacted the seller Cowboy Studio and I was asked to send it back. However, I have not done due lack of time.
I ordered the Rainbow Nikon G to Micro 4/3 lens adapter, but received a Kiwi lens adapter. Although the Rainbow lens adapter's product description says it can focus at infinity, the Kiwi adapter would not allow my 3 Nikon lenses to focus beyond 10-15 feet (so this product is effectively useless).
I was a bit worried by some of the negative comments here but I must say that I am quite impressed by this nice adapter. I bought this to adapt a few of my Nikon G lenses to my new Panasonic GH3. I needed an adapter that allowed manual aperture control and this is one of the few I could find here on Amazon (with Prime shipping!). The only downside is that this aperture control has a very short throw distance, so a tiny turn steps the aperture down a significant amount.
This adapter is sturdy and easy to use. When used  it effectively doubles the focal length of my lenses for my DSLR. My Sigma 17-35 becomes a 34-70, and the Nikkor 35-135 becomes a 70-270, but the f stop stays the same. The only difference is that you have to focus manually  which is no big deal to me since being into photography for over 50 years.
Mine rotated a little past where is was supposed to and has a tiny scratch because of it.List of lenses I have attached:Nikon 80-200mm f/2.8D EDNikon 35mm f/1.8GNikon 18-55mm f/3.5-5.6G AF-S DX VROverall:Awesome product for an awesome price. If you need an adapter with aperture control, this is the one. I was really surprised by how well it was made for what it cost.
the glue on this product is not strong enough to keep the aperture ring level. the ring is still able to adjust the aperture on my lenses, but the poor construction even prevents me from easily moving from f/2.8 to f/2.0 on my nikon af-d 50mm f/1.4 lens. do not buy! not worth the money!
This inexpensive adapter does not have a lot of features and setting the aperture takes some guess work, but it gets the job done. I have tried it with 35mm f1.8G and 10.5mm on my GF1 and was satisfied with the results.You get what you pay for and in this case it is worth it.
It doesn't focus at infinity for a Rokinon or Voigtlander lens that are Nikon mounted on an Olympus OMD EM1. I can live with that since I am not doing landscapes, mostly portraits. The adapter has a little twisty play in it but not up/down or side to side.
I ordered a Nikon lens adapter for my Panasonic Lumix GH-1 with aperture ring adapter, but didn't get the right item. Instead they sent me a KIWI brand with no aperture ring adapter. I have tried to communicate with the seller but did not get any response since Dec. 2010. Very disappointed.
I purchased this so that I could have a few more lens options for an Olympus E-PL2 that I have being that I also have an awful lot of Nikon gear. The aperture ring on the adapter does what it says and though it'd be nice to be able to fine tune the adjustment, I didn't expect such features from this sort of a product. Overall I'm very content with the purchase and would have no reservations about recommending it.
Answer: You set the aperture on the adapter and it rotate the tab on the lens.  It's trial and error, no set markings.