1 Pair Professional Thick Knee Pads With Built-In Precise Ruler, Suitable For Tile Layers, Construction Workers And Gardeners. The Professional Knee Pads Feature A Built-In Accurate Ruler With Clear Markings. The Thick Knee Pads Are 1.5 Inches Thick, Made Of High-Density Foam Material, Meeting Precise Measurement Needs. This Dual-Purpose Knee Pad Product Combines Protection And Measurement Functions.