It's recommended to buy the largest filter size and use it with the stop down filter ring on your other lens. Learn more about the step down ring here https://www.kentfaith.com/SKU0801_11-in-1-step-down-ring-set. 

The connection should fit, but the lens hood is wide and flat, built for wide-angle lenses. There is therefore very little shadowing when used on a 58mm Helios lens due to its narrower angle of view. A higher construction would certainly be better. Just search for - lens hood 49mm normal lens. 

The way u tell is to look at the end of you lens. There will be a 0 with a slash / through it and a number behind it. Match that number to the 58 of this neutral density filter. 

I've never used Hoya ND's, but I have GOBE, KERNEL, ZOMEI, and K&F ND filters. Out of all of them, I like the K&F the most because the colors look great out of the camera and they don't create a vignette around the edges like some of my other nd's which I hate. Because of the great out of camera colors, it gives you more to work with on post-production when you shoot on a flat profile. Also, I've used them during night photography on bulb mode to do light painting and the 4 - 6 stop ones work great for this. Overall, I think for the money the K&F filters are worth it. Awesome product! 

hello , for the 58mm nd filter, as long as your lens size is 58mm, the 58mm filter can work on nikon d3400. Your camera's lens thread size will be marked somewhere on the lens barrel or printed underneath your lens cap. This number is always preceded by a "ø" (diameter) symbol.