Features: _x000D_ Sturdy, easy to operate. _x000D_ This is a set of cutter head of dredging machine. _x000D_ Made of Manganese Steel material,sturdy and durable _x000D_ The blade can be easily removed by a key insert the small hole. _x000D_ There are two small holes under the head of the knife, which can be fit directly with the spring. _x000D_ _x000D_ _x000D_ Specification:_x000D_ Material: manganese steel _x000D_ Collet diameter :16 mm _x000D_ Fit For: Dredging Machine _x000D_ Weight: Approx.220g/7.8oz _x000D_ _x000D_ Package list: _x000D_ 6 x Cutter Head_x000D_ 1 x Key _x000D_ _x000D_ Note:_x000D_ Please note that the type and old type of this product will be sent randomly, and make sure you will not mind before ordering. 1Sturdy, easy to operate. 2This is a set of cutter head of dredging machine. 3Made of Manganese Steel material,sturdy and durable 4The blade can be easily removed by a key insert the small hole. 5There are two small holes under the head of the knife, which can be fit directly with the spring.