"125khz frequency dual magnet card"

Prepaid Water Card with T5577 Chip and Dual-Magnet for 125Khz Frequency Meter Activation

T5577 dual-magnet prepaid water card with 125Khz frequency and ABS material. Features two internal magnets that wake up battery-powered meters via magnetic reed switch, enabling fast data read/write in under 67ms. Available blank or with custom printing/logo.