"35th Anniversary of the Metical"
Composition: Silver .925
Diameter: 38.62 mm
Width: 2.35 mm
Weight: 28.28 g
(news and image by Murtaza Karimjee)
On march 2017 Wolfgang Schuster confirms that this type exists also in copper-nickel and also in gold.
You can order this coin from my friend Murtaza Karimjee's site: