Linon Industrial Metal Four Slot Mailbox Shop

Post Mounted Mailbox - Aluminum Mailbox Post - Mailbox Pole - Metal Mailbox Post - Modern Minimalist Design

I think the introductions to each mechanism on MSDN answers this: Mailslots: A mailslot is a mechanism for one-way interprocess

4 slot pot cores This 4C versatile™ mailbox from US Mail Supply holds four oversized tenant slots, perfect for an apartment, office building, or campus dormitory Easily mounted

4 slot pot core clips and accessories 4 W x 11 h x 6” deep (add the Locking Security Mailbox Extra Large Wall Mounted Mailbox