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This is one LOT (Qty.1) of New Mini-Circuits SMD T8 Series Wideband RF Transformer, Part Number: T8-1T-KK81. Ratio: 8:1 (Secondary/Primary), and Frequency Range: 0.3-140MHz. Case Style: KK81

Data sheet:

https://www.minicircuits.com/pdfs/T8-1T-KK81.pdf

Some reading material:

How RF Transformers Work: http://www.minicircuits.com/pages/pdfs/howxfmerwork.pdf

Balun Transformers: http://www.minicircuits.com/pages/BalunApplicationNote.htm

Case Style and Footprint: https://www.minicircuits.com/case_style/KK81.pdf