Stainless steel V4A (salt-water and grinding dust resistant), Stainless steel. For surface mounting Door station D21DKV Product Description Stainless steel V4A (salt-water and grinding dust resistant) Brand: Doorbird Producer Item No.: 423868533 Type: D21DKV Surface-mounting housing (Backbox) Product Description • Fits only a D21DKV IP Video Door Station • Product Weight 0,440 kg