A4 Hardcover exercise books come in various thicknesses measured by the number of quires they contain. A quire refers to a traditional unit of paper quantity, typically consisting of 24 or 25 sheets of paper folded together. Here's a quick description of hardcover exercise books in 1 quire, 2 quire, 3 quire and 4 quire formats:

The A4 2 quire hard cover exercise book comprises two quires of paper, totaling around 48 to 50 sheets, bound within a durable hardcover. This provides more space compared to 1 quire books and are suitable for longer-term use, such as journaling, coursework, or keeping organized notes for a subject or project.