... bearing typeFormation or layer soft ,medium soft ,hard,medium hard,very hard formationButton size (extra features)Button bit,saw ... me .3> Do you wanna know how to ship the bits to your country? we will arrange this for ... 1/4490-78480-40mediumHard Shale, Limestone, Medium/Hard Sandstone etc.495.2~174.63 3/4- ... 1/2539-83360-40hardSandy, Shale, Quartzite, Hard Dolomite, Hard Sandstone etc.695.~-174.63 3/4-6 ...