Parallel - Fundamental Quartz Crystal,
4MHz Crystal, SMD, 50ppm, 18pF, 180R ESR
4MHz Crystal, ±20ppm Tol, ±50ppm Stab, 18pF, 180Ω, HC-49/US SMD
ABLS Series 4 MHz ±50 ppm 20 pF -20 to +70 °C Surface Mount Low Profile Crystal