Center-hole feature permits extending adjusting screws, cables, puller screws, etc. Straight through the ram. This spring return unit is compact and lightweight. Ideal for jobs having restricted working space. Set includes OTC4120 17-1/2 ton, 2 stroke single-acting hydraulic ram; OTC4012A pump; OTC9650 gauge; OTC24815 tee; OTC9767 hose; and OTC9798 hose half coupler.