Ko-ken Z Series (3/8") vs Koken 3400 Series (regular) Sockets

The premium 3/8" sockets from Ko-ken vs. their more mainstream series - what's the difference??

[@johnh.heartland7952]

I have the Z-series in 1/4, 3/8 and 1/2 - Top quality sockets to work in tight spaces. I wish the markings on them were bigger/wider - Stay Safe

[@oviwankenobi17]

These koken sockets look to be the real deal. You've made me want to try them out!
Looking forward to your next video.

[@themessygarage]

I've really enjoyed using them!

[@victorhoyt4352]

The regular kokens are identical to the tone, and the tone is cheaper. They look to be the same socket with a different name, honestly.