Leather Card Case
You can have this acrylic pattern from here:
http://www.leathercraftpattern.com/Acrylic-template/acrylic-card-case-pattern-A-105
The finished size is: 4.8" x 3.1" x 1.1" (12.2cm x 8cm x 2.7cm).
Advice:
Leather: 2.0mm (5oz) leather, size 26cm x 13cm. 1.0mm (2.5oz) leather, size 43cm x 15cm.
Hardware: 633 snap x1.
Tools: If you are a new leather player, try to considerate to have tool kit here: http://www.leathercraftpattern.com/leather-tools-leathercraft-tools/leather-tool-kit/leathercraft-tools-leather-craft-patterns-leather-art-leather-carving-tool