Purchased from Amazon (Amazon Basics), these are B5 notebooks. New, unused. 30 sheets x 40 notebooks Wide-ruled notebooks, 30 sheets each, blue. Double-sided paper: Designed to resist ink bleed-through Smooth white paper: Suitable for writing with your favorite ballpoint pen B5 size notebooks, suitable for taking notes at work, school, home, or on the go Dimensions: 25.2 x 17.9 cm (standard B5 size) #B5 #b5