Not my video - the guy explaining did a perfect job to outline the moment of the needle. Spoilers below:
There is no needle.
CORRECTION: A user in the comments has shared the specific syringe that is able to retract it's needle and it really seems the same. Big thanks to the person sharing this and for your convenience, I am adding the link here as well -https://www.youtube.com/watch?v=wC-uXq3uUdQ
Not my video - the guy explaining did a perfect job to outline the moment of the needle. Spoilers below: There is no needle.
CORRECTION: A user in the comments has shared the specific syringe that is able to retract it's needle and it really seems the same. Big thanks to the person sharing this and for your convenience, I am adding the link here as well -https://www.youtube.com/watch?v=wC-uXq3uUdQ
Oh, that's right. Thanks for the correction!