Does the 56PB come with a normally open and normally closed contact?
No. The 56PB only comes with a Normally Open Contact, as it is a singular operating button and non-latching.
If they are looking for a stop/start operating push button, they would be better suited to use a 56/2PB as this has both the "start" (N/O contactor) and "stop" (N/C contactor)
Some of the features of this product include.
Green Start Push Button
Red Stop Button
Clearly maked front cover
For further information, please visit http://www.clipsal.com/Trade/Products/ProductDetail?CatNo=56/2PB&c=6&ms=8&s=36&mg=12064