The AC Adapter for TL-2100 series monitors- 9 volt (9 volt battery model)  
           
 
For Use With:  
Low-Cost Bed/Chair Exit Fall Prevention Monitor TL-2100B ( NOT INCLUDED )
Economy Bed/Chair Exit Fall Prevention Monitor TL-2100ET ( NOT INCLUDED )
TamperProof™ Safety Auto-Reset Fall Prevention Monitor  TL-2100ST ( NOT INCLUDED )