The only thing special about it is the special packaging.
Technical Specifications:
3rd Series 5 sen coin
Face Value: 5 sen.
Diameter: 17.78 mm.
Weight: 1.72 gm.
Thickness: 1 mm.
Composition: Stainless Steel
3rd Series 10 sen coin
Face Value: 10 sen.
Diameter: 18.80 mm.
Weight: 2.98 gm.
Thickness: 1.5 mm.
Composition: Stainless Steel
3rd Series 20 sen coin
Face Value: 20 sen.
Diameter: 20.60 mm.
Weight: 4.18 gm.
Thickness: 1.7 mm.
Composition: Nickel Brass
3rd Series 50 sen coin
Face Value: 50 sen.
Diameter: 22.65 mm.
Weight: 5.66 gm.
Thickness:1.9 mm.
Composition: Nickel Brass Clad Copper