Two-phase, low-profile cylinders use 3,000-psi hydraulic pressure for piston extension and plant compressed air for retraction. The design saves energy and requires less space than mechanical springs. Products are available in seven sizes from 3 to 6-in. OD, with extending forces to 31,900 lb and retracting forces to 1,400 lb, using 100-psi plant air.

Mack Corp., 3695 E. Industrial Dr., Flagstaff, AZ 86004, (928) 526-1120,