Resonators function like crystals, but are a lower cost solution that does not require external caps.
These resonators are +/-0.5% or better from -20C-+80C. These resonators have built-in load capacitors so no external caps are needed.
Ceramic resonators (CERALOCK) are made of high stability piezoelectric ceramics that function as a mechanical resonator. This device has been developed to function as a reference signal generator and the frequency is primarily adjusted by the size and thickness of the ceramic element.