Very easy to install. I drilled out the jam release hole to the same size as the t-pull post and it fir perfectly. The spring primes to reinstall and also drops in easily. The details on the loading door are a nice touch. It is now much more comfortable to prime.
Kronos Mod Kit
The loading door and spring were very nice upgrades, and the lubricant was a welcome addition to the package, but the amazon-exclusive repaints of the kronos are the same as the red and blue ones, in that they will require a LOT of cutting in order to install the T-pull (due to changes in the shell). For that reason, I can only really recommend this kit if you have an older kronos, or have some experience with integrations and/or shell cutting. This is far from a drop-in upgrade for me, and is going to require a lot of work, or pieces from an older kronos.
So 3 out of 4 components worked flawlessly with my Red Kronos: the loading door, the spring, and the lube. All install as easily as they should and work well. The spring is particularly no joke.
Unfortunately, it turns out there has been a minor revision by Hasbro in the way they mold the slides for the Kronos since the original Phantom Corps version, and while the Phantom Corps version requires just minor shell cutting to install the Worker T-Pull, the later Red and Blue models require EXTENSIVE shell cutting. Far more than I am equipped and willing to attempt.
For the time being, I have instead installed a 3D-printed priming assist/sight to ease priming this heavy spring (it's doable with just the slide, but it's not comfortable) and I intend to pick up a white Kronos down the line to make use of the T-Pull