Packaging for the optical attenuator consists of Tape & Reel (TR) solid enclosures.Shipping overseas is convenient with the RF Attenuator packed in SOT-23-6.You can find the functions of the 6 pins in the RF Attenuator.
HMC291SETR Features
6 pins
HMC291SETR Applications
There are a lot of Analog Devices Inc. HMC291SETR Attenuators applications.