A "normal size towel" is a general term, but it typically refers to a bath towel. These are the most common towels used for drying the body after a shower or bath.

A standard bath towel is roughly 27 inches by 52 inches (69 cm by 132 cm), though sizes can vary.

The "A1" in "Normal Size Towel A1" is likely a product code, model number, or a brand-specific designation used by a retailer or manufacturer. It's not a standard sizing term in the textile industry. It's simply a way to differentiate that particular towel from other products in the same line or store's inventory.