This lens hood of JJC is made of metal and can be easily mounted by threading on my "oldie" Minolta 28mm f2.8 W.ROKKOR MD. The build quality of the lens hood produced in China is very good and she feels "cool" to. In order not to unscrew after each shoot, I have purchased a lens cap with 72mm diameter to JJC. Both products I really like. The shop has delivered quickly. The price / performance ratio, especially due to free shipping, I rate as very good.
Pictures I have set. Buying I can recommend without reservation.
Addendum of 08/01/2015: Meanwhile I use the diaphragm with success on my lens Sony SEL18-55mm.