Long work distance; TD157 restaurant pager system 984ft long range; TD175P restaurant buzzer system work distance up to 500m/1640 ft in open areas Long standby time; TD157 restaurant pager system can work 20 hours after charging; TD175P restaurant buzzer system standby for about 15 hours Multiple prompt modes; TD157 restaurant pager has 2 alert mode; flash+beep; only flash; but no vibration mode; TD175P restaurant buzzer has 7 alert mode set with vibration, flashing and buzzer Simple; TD157 restaurant pager no reprogramming; TD175P lightweight and compact design; suitable for places where the food truck has a small space Large-capacity restaurant buzzer pagers; TD157 restaurant pager 16 Order Ready Buzzers for Restaurant; TD175P pagers 30 order buzzers for restaurant food truck