The part number is CAP CER 56PF 16V C0G/NP0 0603. It is a type of ceramic capacitor with the following specifications: capacitance value of 56 pF, tolerance of ±10%, and operating voltage of 16V. The capacitor has a metric size of 1608 (which is equivalent to 0603 in imperial measurements) and belongs to the C0G/NP0 class, which indicates it is a stable temperature coefficient ceramic capacitor.