1.Size:3 3/4" (95.3mm)~26" (660.4mm) ... compacted shales ,sandstone, clays, salts and soft li mestones. Size and IADC available: 2 7/8" to 26" IADC ... o-rin provides adequate sealing for bearing durability . Model button tooth tricone bit steel/milled tooth tricone bitIADC CODE 116 ... ,medium soft ,hard,medium hard,very hard formationButton size (extra features)Button bit,saw teeth1) Y-Conical teeth 2) X- ...