First, there is a brand when buying. Big brands are trustworthy. Also need to have the 3c logo (CCC is the English abbreviation of "china compulsory certification")
Second, look at the appearance, this is relatively straightforward, the seam of the good patch panel is smooth and flat, and there is no burr flash around the shell. The inferior quality is the opposite. (When you hold the terminal block, you can twist it to see if it can be easily twisted. If it can't be done basically, the plastic case has the address of the manufacturer, etc., and the inferior quality is not)
The three-handed plug is plugged into this jack, and the plug-in board is moderately inserted. (Not very tight or very loose) and the inferior plug-in board is too loose or too tight, and the wire of the wiring board is generally marked with 250v. The wire is also relatively thick. It is a molded plug that can't be disassembled. The place where the switch is pressed is not tight and will not be stuck.