RV Designer Bubble Level Stick On 3 5/8in x 1 3/8". Use the bubble and numbers as a leveling guide. When the bubble is perfectly centered at the zero that means the surface is level. If the bubble is not aligned at the zero mark then the surface is not level. The E401 Bubble Level features a peel and stick application. The dimensions of this level are 3-5/8" by 1-3/8". There are two stick-on levels per package. Features of RV Designer E401 Bubble Level Stick On 3 5/8in x 1 3/8" Ensures surfaces are evenly horizontal or vertical Peel and stick application Includes adhesive sticker with numbers When the bubble is perfectly centered between the two lines that means the surface is level Dimensions: 3-5/8" x 1-3/8" Package Contents: RV Designer E401 Bubble Level Stick On 3 5/8in x 1 3/8" RV Designer E401: Bubble Level Stick On 3 5/8in x 1 3/8"