Parallel grippers feature heavy-duty T-slot design November 22, 2011 By Paul Heney Leave a Comment A new series of 2-finger parallel grippers from Techno-Omil feature heavy-duty T-slot design. Identified as the OPP2-…. Series, these 9 grippers feature a stroke range of from 12 mm to 72 mm and a gripping force of from 420 N to 8410 N.