Where can i find a security camera that can transmit to a laptop without internet or wires?

So my friend is starting a sensual mage business. He and I are going to be security he has a hidden camera that transmits to his TV. What I want to know is there some sort of small camera that can wirelessly transmitted to my laptop while I'm downstairs with other clients? So we can both keep an eye on things? If so Please provide me with a link. If no such thing exist. Can someone point me in the direction of where I can find a nice color small discreet camera that can transmit to another TV downstairs? we may consider buying a TV for downstairs incase there is no such thing that transmits to a lap top