POSGuys.com features restaurant paging systems from Command Communications.

Restaurant Pagers

Restaurant Staff Pagers are designed to streamline the communication between managers, servers and the kitchen. By giving each of your employees a device you will have the ability to notify them when key events happen, such as
notifying servers their food is finished at the kitchen, and ready to be served to the patron. Servers can also reach the managers for any applicable situation, such as POS manager overrides or a patron requiring immediate attention. 
If you have a multi-story restaurant where communication is limited by the sheer size, or you just want to improve communication all together, then this is the solution you have been looking for! 
Customer Pagers are similar to the Staff Pagers in functionality, but Customer Pagers are for you to hand out to customers waiting for a table. This allows them to wait in an area away from the hosts station and have a more enjoyable experience, especially if they go to the bar to spend more money, increasing your overall profits. The pager base station has a 1 mile range so you don't have to worry about them being too far away to be paged. 
These pagers also conveniently recharge by stacking them on top of the base station ready to be used on demand.

Restaurant Pagers

Restaurant Pager Kits

Long Range Systems Guest Paging Kits

Long Range Systems Staff Pager Kit

Restaurant Pagers

Long Range Systems Coaster Guest Pagers

Long Range Systems Staff Pagers

Restaurant Pager Transmitters

Long Range Systems TX-9561MT