You can download ev3b file to import this block：Latest Release
What’s EV3 ToolBox Block？
EV3 ToolBox Block, a practical EV3-G toolbox block developed by OFDL Dev. and T2H robotics team, is designed to provide some functions that EV3-G software does not use for you, or made some useful block into block.
There is lot of funcs：atan2、Select、Mapping、Max and Min...etc.
使用說明：https://ofdl.tw/ev3-hack/ev3-toolbox-block/
User Guide：https://ofdl.tw/en/ev3-hacking/ev3-tool-box-block/