HCM49 7.3728MABJ is a quartz oscillator manufactured by Citizen, a Japanese quartz watch and clock movement manufacturer. It is a 49 kHz quartz resonator designed for use in high precision timepieces, including watches and clocks. It features an ultra low frequency of 7.3728MHz, an ultra high frequency tolerance of ±20ppb, and a temperature rated from -30°C to 85°C. The device is miniature in size, with dimensions of 3.2 x 1.5 x 0.9mm, making it an ideal choice for a wide range of timekeeping applications.