Easy to Install: This thumb clamp suitable for excavators of 3 tons and below. Equipped with 2 pieces M14*15mm(0.59 inch) threads hydraulic oil hoses Strong Grip: Thumb clamp with uneven teeth on the bottom. Operated by the hydraulic system of the excavator for better gripping Sturdy Materilal: This hydraulic thumb clamp is made of manganese steel.Strong and durable, not easy to bend. Can withstand harsh working environments Wide Application: This hydraulic thumb clamp can be adjusted to different angles and used with the excavator's bucket. It can grab heavy objects such as rocks, wood, scrap material Connection size: It fits the diggers with 3 holes in the arm. The connect hole diameter is 25 mm/0.98 inch.