The battery holder holds a CR2032 battery providing 3v.  It is compatiable with commercially availabe bricks or works with sewing based applications.
The battery holder is designed to connect to other components like the brick based LED using 1/8th inch wide conductive tape. We recommend conductive cloth tape,  it is easire to work with.  
The battery holder can also be used with Conductive Thread to create wearable, Soft Circuits.
You can also use alligator clips to connect this battery holder to other components.