Multilayer epoxy coated Monolithic ceramic capacitors in NPO ( COG ) Class 1 and X7R ( Class 2 ), brands include AVX, TDK, Torch, Hitano, and Vishay.

MLCC NPO ( COG ) class 1 capacitors are temperature stable and suited to RF oscillators and constructing low loss RF filters.  X5R/X7R class 2 types are temperature stable and are suitable where moderate capacitance changes are acceptable and suitable for audio and decoupling of power supplies etc.  Z5U/Y5V class 3 are for general purpose use and mainly used for power supply decoupling.  The 50 volt versions are suitable for up to 10 watts of RF, and the 200 to 250 volt versions should be suitable for up to 100 watts of RF.

Refer to the part description for capacitance, temperature, voltage, and lead spacing.

Data Sheet for TDK FK Series capacitors  Data Sheet for Hitano Multilayer capacitors Data Sheet for Torch Multilayer capacitors

It appears that most leaded NPO Monolithic capacitors will soon be unavailable as most manufacturers have stopped production.