Bulk is the solid enclosure in which optical attenuator is packaged.Shipping overseas is convenient due to the RF Attenuator's packing in 1206 (3216 Metric).
E-TA3216 4DB N8 Features
E-TA3216 4DB N8 Applications
There are a lot of Nidec Copal Electronics E-TA3216 4DB N8 Attenuators applications.