1. Internal reverse and overcurrent protection, 30V protection voltage.2. -in one single 3.7V lithium battery supply; the using time varies, based on the usage (It can be more than 6 hours with 20mA continuous output).3. With internal battery voltage , (UV light)when the undervoltage light is on, please turn off the charging.4. Do not for a long time, please charge once two months. Charge with -USB (Not Included). Operating temperature range 0-50 degrees Celsius.5. The signal generator is mainly used for debugging of industrial field PLC, process instrumentation, electric valve and so forth. It's easy to with a Chinese character operation interface. The signal generator is small and light but has a long standby time and high . Conversion Function:This function is mainly used for some temporary voltage and current conversion, such as converting 0-10V input to 4-20mA output. conversion: converts the voltage signal input into an current signal output passive conversion: converts the voltage signal input into a passive current signal outputC-V conversion: converts the current input signal into a voltage signal outputThe function rules consist of parts: conversion switch, conversion mode, voltage upper limit, voltage lower limit, current upper limit, current lower limit, and overrange.Specifications:Name: Signal Generator current output: range: 0-24mA; resolution: 0.01mA; maximum load: 750Passive current output: range: 0-24mA; resolution: 0.01mA; external supply up to 30V.Voltage output: range: 0-12V; resolution: 0.01V; maximum current 30mA24V voltage output: drive current: 24mA.Current input measurement: range: 0-24mA; resolution: 0.01mA; input impedance: 100Voltage input measurement: range: 0-30V; resolution: 0.01V;input impedance: 2.5MOperating environment: 0C-50CProtection voltage: 30VItem size: 90 x 70 x 28mm / 3.54 x 2.76 x 1.10inMaterial:plasticcolour:BlackPackage Contents:1 x Signal Generator3 x Test CableOnly the above package content, other products are not included.Note: Light reflection and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.