This little bag is more than a phone sling. It has enough room for any smart phone and possibly a slim wallet. The back has a card slot where you can slip in 2 to 4 cards. Easy access from inside and the back.
 
Material: vegetable tanned leather in Black from Conceria Walpier Srl
Dimension: H 8" x W 4.5", D 1.5"
 
Two Options for the strap: 
-Strap with button studs for adjustable length (45-56inches)
-Simple Leather lace (50 inches)