求翻译：水浴恒温振荡器是一种温度可控的水浴恒温槽和振荡器相结合的生化仪器，是生物、微生物、遗传、医学、环保等教育、科研和生产部门作精密培养制备不可缺少的实验室设备。其主要特点：1）温控精确，数字显示；2）设有机械定时或常开；3）万能弹簧试瓶架特别适合作多种对比试验；4）无级调速、运转平稳、操作简便安全。5）带“A”型具有速度显示功能。是什么意思？

Water bath thermostat oscillator is an oscillator and temperature-controlled water bath thermostat combination of biochemical equipment, is biology, microbiology, genetics, medicine, environmental protection and education, research and production departments for precision preparation training essential laboratory equipment. Its main features: 1) temperature control precision, digital display and 2) have a mechanical timer or normally open; 3) universal spring trial bottle racks are ideal for a variety of contrast test; 4) to stepless speed regulation, smooth, easy to operate security. 5) with "a"-type with speed display function.