Purchased 4 mags at ~$9.60/each with 20% off discount code. Shipping was free and there was no state taxes
Took around 3 weeks from day of order to arrive to me in Washington State.
Packaging was nice and it had a styrofoam mold to it inside if a cardboard box.

These seem to be B-grade mags compared to mags I’ve seen online from elsewhere, and are noticeably more “rushed” than the mag included with the S200 I also bought from ZhenduoToys. So its a good idea to have some plastic lubricant and a set of needle files for smooth loading and feeding. The spring in these though us about the same as the mag included with the fire rat, which is to say it is kinda weak and cheap. Not only is the mag thin (which is understandable) but the build material and quality are both poor, so if you have the money I’d splurge for the metal mags.

Before lubing and filing the loading and feeding was not smooth especially after 4-6 rounds. Feeding occasionally hiccuped even if fired casually and deliberately.
After a few minutes of lubing and filing it fired fine. Keep in mind the diameter of these is pretty skinny compared to Worker half length mags so loading had to be more deliberate.

Overall I bought this because it was on sale, shipping was free and I was in no rush to get it. At $12/ea it is more expensive than Monkee mods at $6.25/ea but shipping was free while shipping to monkee mods to me is $20+ minimum (albeit monkee mods shipping is faster). I do believe that Monkee mods mags are newer gen and likely have better quality control. I am awaiting for US-based retailers like Out Of Darts to stock these so I can get a cheaper price, better QC and faster shipping.
Despite language barriers, Customer service from Zhenduotoys was excellent.