These heavy duty thumbs add versatility to any excavator or backhoe loader. All Blue Diamond excavator thumbs can be used manually or hydraulically. Every hydraulic thumb includes a stiff arm, so in the event you are not able to use your cylinder, the stiff arm can be installed to continue working! These well engineered excavator thumbs fold tight to the boom when not in use and the stiff arm stays with the unit when folded. Hydraulic thumbs do not come with hoses or couplers.