Package included:<br />1x  10mm woodworking square hole drill<br />1x 16mm woodworking square hole drill<br /><br />product specification<br />model:521080<br />name:square hole saw mortising chisel <br />material:metal<br /><br />square hole size: 16mm 10mm<br />slotted depth:      77mm 61mm<br />total length:        218mm 195mm<br />clamping diameter: 19mm 19mm<br /><br />application:mainly used for carpentry｣ｬ applicable to the construction｣ｬ installation｣ｬ decoration｣ｬ decoration industry use.<br /><br />use:<br />square hole drilling is used in the square tenon hine｣ｬ specially used for a drill square hole｣ｬ it can not be used on electric drill.