It is packaged using the Tape & Reel (TR) method since it is a clock IC. RF synthesizer is comprised of CLOCK GENERATOR, PROCESSOR SPECIFIC uPs, uCs, and peripheral ICs.
SI5351C-B09809-GMR Features
SI5351C-B09809-GMR Applications
There are a lot of Silicon Labs SI5351C-B09809-GMR Clock Generators applications.