Aaron, these could be either "Polymer or Steel" (https://us.glock.com/Products/g17_gen5_mos_fs) as Glock offers both. My guess would be Polymer but I would confirm with Glockwith the model #PA175S203MOS
at : https://us.glock.com/en/contact-us

the sights are a polymer Picture shows a optic mounted the optic is not included just the optic mounting system The slide is precision machined to provide a mounting system for popular optic sights. With multiple adapter plates, you can quickly and easily mount miniature electronic sights to the rear of the Gen5

Aaron, This specific firearm has factory plastic/polymer sights. White outlined goal post rear and blade front. Acronym MOSFS on this description means "Modular Optic System, Factory Sights" All the Gen 5 upgrades. Great piece.