The Material is Default Blin with Ambient Occlusion Texture assigned to Ambient Color.
The unit of measurement used for the model is Centimeter.
The type of rigging used is simply a Blind Shape Deformer.
Rigged to be 3 different models : Basic Shape Blown Up Shape Empty Balloon shape with a simple 1 and 0 Attribute .As descried in the images. The Attribute can be animated to transform from one shape to another.
So its a very interesting transformable Letters.
It can be used for typography projects or as a Print Ads.
The Model is Done By Maya 2015 and Rendered using Mental Ray. OBJ is Attached as well.