The adaptor rings that attach directly to your lens are metal. The filter holder that attaches to the adaptor ring is metal. The frame around the CPL is metal. The detachable frames around the square filters are molded plastic. 

Hi, this is a completed Suqare filter X PRO System, with a filter holder, filter, filter adapter rings, and filter pouch, if you want an individually filter holder or filter, we are also on sale. 

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) 

K&F have a list of which adapter will work for each lens to camera combination they support 

hello panasonic lumix g7 is m3/4 mount, so the adapter ring could not work for panasonic lumix g7