The fiber coupler adjustment key consists of an eccentric adjustment head and a knurled hand grip. The eccentric head is inserted into the fiber coupler through the adjustment port, and rotating the knurled handle moves the coupler lens to achieve focus adjustment. Currently, the 85EK-08 eccentric adjustment key is compatible with the three-axis FP3 series, while the 10EK-10 eccentric adjustment key is compatible with the adjustable-focus ADFC series. In addition to standard models, LBTEK also offers a variety of custom eccentric adjustment keys. For specific customization requirements, please contact LBTEK Technical Support.