Looks like chrome plate.

The investment casting process provides a very high quality of casting with exceptional surface finish. Because of this, stainless steel castings can be mechanically polished to create a finish which is virtually identical to a chrome plated finish.
To achieve the required base casting it’s essential that the process control is good and DGI use a casting simulation package to ensure they produce the very best investment castings which are free from porosity and surface defects. Once polished, even if the parts become damaged, they are relatively easily recovered with mechanical polishing. If plated, they would have to be stripped first, reworked and then re plated, which often makes it uneconomic and results in expensive scrap.
The process of mechanical, mirror polishing of investment castings is often used for furniture or decorative items including beer dispense pumps.