They look beefier.
Plastic hub keeps the screws clean of grass and debris. They will send you some.
Not only do the plastic hubs keep the screws free of debris, they also act as a buffer for the actual lock nut and spindle shaft to make it so that just in case it does run over something, it hits the plastic first and can spin on that before the shaft makes contact.
Just to be clear, when I got the new caps and installed them, I did use the tightening torque provided above and I did also use the blue lock-tite as advised.
I figured it was some way to hold down the blade by distributing the forces from the two screws, but your explanation about protecting the shaft sounds better.
You gotta protect that… It’s important. 
Especially the nut! Don’t forget about the nut! 
Yes, it keeps that covered for safe keeping.
Has anyone figured out how to purchase replacement caps? I don’t see them on the website anywhere. Mine got shredded today as well.
Reach out to support. They will send you some. I wish they came with the replacement blades, but alas, they do not.
Yeah, I found out too late that the applied thread locker was not far enough down the screw. One blade was missing, found in my yard, the other was hanging by one screw
The issue is that the new caps are much more sturdy/beffy than the ones that came with the unit, so Yarbo should send replacements in advance. Otherwise there will be many more service calls for lost blades. I am going to try and make a 3D model for the sturdier caps, if I can.
You can contact our support, and they will be happy to help you with the replacements.
I have been trying to contact support for 2 days to no avail. I put in a ticket and attached photos, emailed support with photos, and yet I’m still left with a non-functional mower due to having no blade caps. I’m sure it’ll take a week to ship them once I finally get an acknowledgement. Yarbo Team, you really need to be getting back to folks within one business day for a simple issue like this. The grass here is getting taller by the day. If you had them for sale, I’d purchase an extra set just to have on hand for situations like this.
At this point, I would suggest giving them a call. Hopefully that will get things going for you.
I have seen people run them without them. While I don’t advise this long term, that will get you back up and running while you wait.
Sorry for the delayed response. I’ve already reached out to our team and asked them to prioritize your case and get it resolved as quickly as possible.
Here’s a quick/dirty 3D file for the mower cap. Maybe someone less clueless in 3D modeling than I am can clean it up. I think if you print it with 100% fill it’ll be plenty strong, even with my ragged scan:
wow, glad I found this. I was out in my yard today and saw one of my blades just sitting in the yard. Fell off my Lawnmower Pro during some recent job! Fortunately the cap was sitting next to the blade, but the bolts are no where to be found. I pulled the mower, and fortunately had spare bolts so I could reattach it. I checked the other blade and it was very loose as well. The original bolts did not have any visble thread lock on them fwiw. I just ordered some locktite and will pull everything apart and reassemble when it gets here.
Tad scary tbh.