Get your fanny pack by SKco.
This waist bag has everything. 
The right size, a small inside pocket, and adjustable straps.

• 100% polyester
• Dimensions: 6.5″ (16 cm) in height, 13″ (33 cm) in width, and 2¾″ (7 cm) in diameter
• Water-resistant material
• Top zipper with 2 sliders
• Small, customizable inner pocket without zipper
• Silky lining, piped inside hems
• Adjustable straps with plastic strap regulators