Chevron Drag Bit - three wings, four wings

Sinodrills Chevron Drag Bit
Chevron drag bit: three wings chevron drag bit, four wings chevron drag bit;
Drag bits diameter: 76mm to 445mm;
Drag bits thread sizes: 2 3/8" API Reg, 3 1/2" API Reg, 4 1/2" API Reg, 6 5/8" API Reg, etc;