The Mini 101 Water Level Meter is a very compact and easy to carry meter available in 65 ft (20 m) lengths. A choice of probes with extra weights has a maximum diameter of 0.313” or 0.375” (7.9 mm or 9.5 mm). The narrow tape is accurately marked each 1/100 ft or 1 mm. It is ideal for use in any narrow diameter application, where high accuracy is desired.