Our adapters support to focus to infinity. Since it's a manual adapter, if you come with this issue, please try to set the camera as MF (manual foucus) mode, then turn the focus ring to the infinity (∞), and try to turn back a little to achieve focus to infinity in case the infinity mark of some lenses is not accurate enough. Besides, the position of the infinity mark [∞] of the telephoto lens or super telephoto lens is shifted slightly to the positive side to enable focus adjustment even when focus shift is caused due to temperature changes. Please be sure to check the focus through the viewfinder even when you shoot at infinity. 

Could you please update us your full Minolta lens model ?as Minolta has MD MC and AF mount, K&F Concept MD-M4/3 is suitable for: Lens: Minolta MD MC Mount lens(not for Minolta AF mount: KF06.157) Camera: Micro 4/3 (MFT) mount mirrorless camera like Olympus PEN, OM-D series, Panasonic Lumix DMC-G1, G2, G3, G10, GX1, GH1, GH2, GF1, GF2, GF3, GF5, GH4, Panasonic AG-AF100 Mirrorless Digital Cameras, Black Magic Pocket Cinema Camera (BMPCC) 

No, it's just the filter with case. But any brand of 100mm square filter holder kit will work (Lee, Kase, Nisi, Tiffen, etc) which accept 2mm thick glass filters. I have Kase one. 

Any lens that use the M42 size screw in mount. The only other screw mount is M39 and these won’t fit, they would need a different adaptor. They will invariably be vintage lenses and you will only be able to use them in the aperture priority or manual modes, stopping town the iris when metering. Search on EBay for “M42 lens”, that will give you an idea of what you can find. 

It can't not be fixed well with the lens without the adapter ring. you should buy another adapter ring of 95mm size if you want to make this square filter fixed on the lens.