Corded wrist straps are recommended.
Why are cordless wrist straps considered a killer for electronics factories? Let's start by explaining how corded wrist straps work. Corded wrist straps connect the human body to an anti-static ground wire via a wristband and a conductor. Static electricity generated by the body is conducted to the ground through the anti-static ground wire, thus dissipating the static voltage, which can be controlled to almost 0V. Now let's look at the working principle of cordless wrist straps.
Cordless wrist straps discharge static electricity from the body through corona discharge, similar to the working principle of anti-static gowns. Therefore, the static voltage can only be controlled to around 1000V. Some electronics factories are unaware that their products have a withstand voltage below 1000V, requiring the use of corded wrist straps. Using cordless wrist straps would be detrimental to product quality and become a "killer" for electronics factories.