The Holga 120N replaced the 120S around 2003. The significant updates were the addition of a tripod mount, interchangeable film masks for 6X4.5 and 6X6 and the big change is an aperture setting switch that actually does something. The N also added a Bulb setting for use with flash or long exposure.
(I tape my N/Bulb switch so it does not get accidentally switched to Bulb.)
The original Holga 120S had a slide that showed a cloud/flash symbol on one side and a sun symbol on the other. Moving the slide did absolutely nothing. It was always f8. With the 120N the slide actually worked. Now you have the option of f8 on the cloud and f11 on the sun. I should say approximately f8 and f11, they are far from precisely calibrated. Play with your version and see where it actually shoots, or if it is even consistent. Welcome to Holga.
The lens is still the plastic 60mm and focus is still zone with icons. The N also added a film mask for shooting 6X6. You could shoot 6X6 in the S by taking out the 6X4.5 mask, but you ran the risk of light leaks and scratching your film one the sharp body edges. A common mod to the S was to just tape the rails where the film touched to limit scratching. Light leaks, more tape. Like the 120S the 120N was original available in black but eventually was produced in every color imaginable and a few more. Lomography picked up the Holga line and did a number of special releases.
In 2015 Universal Electronics the company that produced the Holga, ended production. But take heart, hipsters: a new company has picked up production and the Holga is available again.
I have a soft spot for the Holga. I am not willing to pay retail for them, but when I find one at a camera show or thrift shop for a few $, I am always tempted and generally leave with more plastic. Fortunately it is a cheap habit. I also have a stash of expired film both 120 and 35mm. Putting film of questionable quality in a Holga feels like a logical match.
Lens: "Plastic Fantastic" Optical Lens f8 60mm
Film: Kodak Porta 400 B&W expired