JW1511 mechanical adjustable polarizer is a test equipment with excellent performance specially designed by Shanghai Joinwit for the current polarization related test. Through the high-density design, the equipment footprint is greatly saved, and the input light can be arbitrarily converted into linearly polarized light, with high extinction ratio and small insertion loss value, and different polarization state measurement needs can be met through 360-degree adjustment. It is very suitable for monitoring the change of polarization state with time, measuring polarization extinction ratio and constructing variable beam splitter.