TOPS Laboratory Research Notebook, 9.25 x 11 Inches, Carbon, 100 Numbered Sets, 100 Sheets, White and Canary (35125) Numbered sets Quad rule (4x4) on front only Plain back Lab Research Notebook is ideal for lab work and documenting results Carbons allows you to create a duplicate as you accurately record data 100 numbered sets 4 squares per inch, One sided Features (white/canary) with carbons for duplicate records. The included carbons allow you to create a duplicate as you accurately record data. Canary duplicate sheet is perforated for easy removal while the original remains for records.