Apera Instruments Value Series Salt20 Salinity Tester Kit (AI214) auspowers_batchfour Perfect Fitment For Shaft diameter B0CQC51ZQ9 Perfect Fitment For Shaft diameter 3 4" and hubs wheels diameter 1 3 8" It also allows you to be able to connect to different types of connections without changing tools and hoses Apera Instruments Value Series Salt20 Salinity Tester Kit (AI214) Apera Instruments Salt20 Pocket Salinity Tester Kit is built for professional salinity measurement of general water soliutions including pools& spas agriculture education environmental monitoring etc Range 0 10 0 ppt Accuracy 1% F S 1 point auto calibration 0 to 50˚C auto temp compensation The BPB (Brush Resistant Platinum Black) sensor adopts Apera's special processing technology which minimizes electrode polarization expands measuring range and increases firmness of the electrode hence ensuring a much higher accuracy and consistency in a wide range salinity measurement than traditional stainless steel electrodes and is easy to clean The large LCD screen has ppt temp value dual display and indications of completed calibrations and stable readings Practical functions to make your salinity testing easier and more reliable 2 point auto calibration 0 to 50˚C auto temp compensation Self diagnosis with out of range and low battery warning Complete kit Salt20 meter 1 bottle of calibration solution AAA batteries and a lanyard all in a portable carrying case IP67 water resistant Up to 1000 hours of use powered by 4 AAA batteries Low power alarm and auto power off in 8 min if no operation The product is CE and RoHS certified and is manufactured under an ISO 9001 2015 certified quality system