Small heating system that is placed on the hearth of a shisha pipe to improve the combustion system. . grid: semi flexible. reusable. fits all fire pits less than 7cm in diameter. . dimensions: lid: height x diameter (cm). 2.2 x 7.3cm. . grid: thickness x diameter (cm). 0.02x9cm. . chimney: height x diameter (cm). 6 x 0.9cm