Specifications: It can quickly clean-up biological samples and extracts to routine clarification. This qualitative filter paper has 7-18cm diameter specifications, which can fully meet your needs. Made of high quality paper, it has good filtering performance and strong absorption. Quantitative filter paper is mainly used for gravimetric analysis experiments and corresponding quantitative analysis experiments after filtration. Through special treatment, the filter paper does not produce chemical reaction with the solution, so as to accurately measure the quantity of a certain component in the solution. Usage Steps: Fold the filter paper in half, twice in a row, and fold it into a 90 degree central angle shape. Press the folded filter paper into three layers on one side and one layer on the other side to form a funnel shape. Put the funnel-shaped filter paper into the funnel. The edge of the filter paper should be lower than the edge of the funnel. Pour some clean water into the mouth of the funnel to make the soaked filter paper abut the inner wall of the funnel. Pour out the remaining clean water and set aside. Place the funnel with the filter paper on the funnel stand for filtering (such as the ring of the iron stand), place the beaker or test tube that receives the filtrate under the funnel neck, and make the tip of the funnel neck lean against the wall of the receiving container on. When injecting the liquid to be filtered into the funnel, hold the liquid beaker in the right hand and the glass rod in the left hand. The lower end of the glass rod is close to the lower surface of the third layer of the funnel, so that the cup mouth is close to the glass rod, and the filtered liquid flows out along the cup mouth. And then tilt along the glass rod and flow into the funnel. The liquid flowing into the funnel should not exceed the height of the filter paper in the funnel. When the liquid flows down the funnel neck through the filter paper, check whether the liquid flows down the wall of the cup and pours it to the bottom of the cup. Otherwise, you should move the beaker or rotate the funnel so that the tip of the funnel is firmly attached to the wall of the beaker, then the liquid can flow down the wall of the cup. Item Name: Filter Paper Material: Paper Quantity: 100 Sheets/Box Product Specifications: 7cm, 9cm, 11cm, 12.5cm, 15cm, 18cm Features: Round, Experimental Test Paper, Multiple Specifications Size: 7cm: Filter Paper Diameter: 7cm/2.76", Product Size: 7 x 7 x 2cm/2.76" x 2.76" x 0.79" (Approx.) 9cm: Filter Paper Diameter: 9cm/3.54", Product Size: 9 x 9 x 2cm/3.54" x 3.54" x 0.79" (Approx.) 11cm: Filter Paper Diameter: 11cm/4.33", Product Size: 11 x 11 x 2cm/4.33" x 4.33" x 0.79" (Approx.) 12.5cm: Filter Paper Diameter: 12.5cm/4.92", Product Size: 12.5 x 12.5 x 2cm/4.92" x 4.92" x 0.79" (Approx.) 15cm: Filter Paper Diameter: 15cm/5.91", Product Size: 15 x 15 x 2cm/5.91" x 5.91" x 0.79" (Approx.) 18cm: Filter Paper Diameter: 18cm/7.09", Product Size: 18 x 18 x 2cm/7.09" x 7.09" x 0.79" (Approx.) Notes: Due to the light and screen setting difference, the items color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 Box of Filter Paper