Mail Slot Sleeve

Residential Mail Slots: Enhance Your Doorway stainless steel mail slot Total Slot Dimensions: 13 in W x 4 in H; Door Dimensions: 10 in W x 2 in H; Weight: lbs; Stainless Steel Finish; Mail Slot Sleeve Sold Separately stainless steel slot drain system Stainless Steel 1 Finish Ives Stainless Steel Mail Slot Sleeve for 620 621 and 622 Letter Box Plates for 1 34 Hollow Core Doors Model: 601 $ Compare

stainless steel t slot bolts mail slots, however, was unable to understand it Hence request you to kindly share me the below details: 1 What is a mail slot in MSL ? 2 Why is it used