MSAST042SCG2R9CWNA01 is a part number for a specific capacitor. The CAP CER 2.9PF 25V C0G/NP0 01005 component has a capacitance value of 2.9 pF with a tolerance of ±0.25pF and operates at 25V DC voltage rating. This ceramic capacitor is classified as C0G or NP0, which indicates its high stability and low loss characteristics over a wide temperature range.