Cut Tape (CT) solid enclosure protects the optical attenuator.Shipping overseas is convenient due to the RF Attenuator's packing in 0805 (2012 Metric).
E-TA2012 T 3DB N5 Features
E-TA2012 T 3DB N5 Applications
There are a lot of Nidec Copal Electronics E-TA2012 T 3DB N5 Attenuators applications.