ITEM NAME:7Pcs 16Mm Steel Drain Cleaner Machine Combination Cutter Head Set E6U3 7Pcs 16Mm Steel Drain Cleaner Machine Combination Cutter Head Set E6U3 Fit For: Dredging Machine Sturdy, easy to operate. This is a set of cutter head of dredging machine. The blade can be easily removed by a key insert the small hole. There are two small holes under the head of the knife, which can be fit directly with the spring. colour:black Material: Steel Spring Junction Diameter: 16 mm Package Contents: 6 * Cutter Head 1 * Installation tool