1.Can be hydraulic type or mechanical type. Hydraulic type is driven by two vertical cylinder(one cylinder plus one linkage design is also available for synchronizing).Mechanical type is driven by the bucket cylinder .

 2.Cylinder's pistons are well protected by steel shroud preventing them from being damaged.

 3.Oil hose are covered by plastic casing for protection .

 4.The cutting edge can be teeth made of cast steel or a welded patch made of wear-resistant steel.

 5.Can be rotary type or non-rotary type.Rotary type is fitted with a integrated rotator which is capable of 360 °  rotating.

 6.Two  extra pair of oil pipe and valve has to be added to the excavator for rotary type log grab.One extra pair of oil pipe and valve has to be added to the excavator  for non-rotary hydraulic type log grab.