The 228 Series from Oscilent is a RF Quartz Crystal with Frequency 32.768 kHz, Frequency Tolerance ±10 to 100 ppm, Drive Power Level 1 µW, Load Capacitance 6 to 12.5 pF, Shunt Capacitance 1.5 to 2 pF. Tags: Surface Mount. More details for 228 Series can be seen below.