... testing and SISI, ABLB, Stenger, etc. Special test, but also has the following features: o Fast ... use. simple keyboard operation, easy to use. Test results can be quickly detected, large-screen liquid ... . Error less than ± 1%. Special Features: SISI test amplitude can be modulated 5,4,3,1,0.75 ... can be 0-110 dB SPL continuous adjustment. Portable design, easy out for doctors audiometry. external printer ...