MODEL JZP-2.5B-SC Rubber Shock Absorber – Solvent-Resistant Body, Self-Locking Fastener Interface A 2.5 kg rubber-metal isolator for production areas where cutting fluids, hydraulic oil and cleaning solvents attack the elastomer and where vibration slowly backs out the fixing bolts. Rated load2.5 kg Natural frequency41.5 ± 5 Hz Static deflection≤ 0.3 mm Working temperature-45 … +65 °C Mounting threadM4 Body sizeØ46 × 30 mm Short answer. The JZP-2.5B-SC is a 46 mm rubber-metal