Maglite Model number: S2D016
2D indicates that it's a 2 D-Cell Maglite
016 indicates that it is Black in color and packed in a Blister/Hanging Pack. If it ended in 015, then it would be Black and packaged in a box.
S2D016 - 2D Black Blister
S2D015 - 2D Black Boxed
S3D016 - 3D Black Blister
S3D015 - 3D Black Boxed
S2D036 - 2D Red Blister
S2D035 - 2D Red Boxed
There are Blister (Hanging) packs as pictured here:
and there are Boxed Maglites as pictured here.
and there are Boxed Maglites as pictured here.
The Boxed and Blister Maglites are identical in every way except for the packaging. So, the S2D016 and the S2D015 are the exact same flashlight.
I hope that helps!