Part Number: HPF3500M -- High Pass Filter (LTCC Construction) Pass Band 3.9G-9.8 GHz. SKU#: AK28_001M.
Enclosure uses RF Design Kit with dimension 0.9375"x0.75x0.59". S-Parameter of part measured on VNA (3 GHz to 10 GHz) is shown in third picture.
Proudly Made in USA by Lotus Communication Systems, INC. in Massachusetts (www.lotussys.com).