Nicolock TH 2X14X4 BS 4' x 2" x 14" Thermal Finish Tread Bluestone give patios, pools and entryways a whole new look with the smooth surface of our thermal-finished treads. These caps can be used with most of Nicolock’s outdoor stone steps and paver stones. Adding them increases the height of the step by 2 inches, providing a finished look with a bit of overhang.