This handheld scanner has an abundant memory capacity, able to store frequencies in 5500 memory channels. Plus, you can store up to 16,500 ID codes in one "working" 500 channel, 1500 ID code scanner with 11 "virtual" scanner pages of memory! This scanner follows APCO 25 digital and virtually all analog Motorola?? and GE/Ericsson EDACS trunked systems. More and more cities are using these trunked systems, allowing city services to share the same set of scanner frequencies. Conversations on these systems start on one frequency, then shift to a different one with each transmission. This scanner can follow these systems. Patent Pending.