At 1.10 euros per piece, it is a good price for a cobalt drill with a diameter of 4.2mm.
Don't forget, the secret to making cobalt drills last a long time is low speeds and lubrication.
If there is no oil, even a little water will do the job.
Just make sure not to overheat and burn the cobalt coating on the tip.

It requires patience to drill aluminum with a thickness of 1.2mm. The time is naturally longer for iron holes. It is not suitable for professional use.