I want to purchase a battery operated door bell?

Stick the button on beside the front door. Put the remote bell inside on the wall with velcro.

Item 77758 you are referring to is only a wireless push button. You will also need a wireless doorbell to go with this item. There are also many wireless doorbell kits that have both push button and doorbell in the same package. Battery operated doorbells are easy. Simple place the appropriate batteries into the doorbell and place it where you want it. Wireless push buttons have included batteries. There is a small orange battery tab that needs to be removed, then your new push button is ready to go.