You are bidding for a black bra. But I am using the photos of the same bra in nude as you can see the strap details more clearly. 

The Flexifit minimiser bra is a fabulous range of seamfree bras, offering a sleek seamless outline to you body contours and reducing bust by up to one cup size.  The cups are full coverage are underwired. The adjustable straps can be changed to create a racer back for cross back tops, or wear in the conventional way.    

There are double fasteners at the back with three adjustment settings. The larger sizes have 3 fasteners.  The bra is moulded.