OTTO Excavator Parts Zx120 4Bg1 Valve Spring Big 1125610996 112561-0996 1-12561099-6 For Isuzu OTTO Isuzu ZX120 4BG1 Valve Spring Big 1125610996 – 100% genuine OEM part for Isuzu ZX120 4BG1 mining excavators. Resists high temp, pressure & heavy vibration, outperforms cheap aftermarket big springs. Slashes downtime & cuts maintenance costs for heavy-duty mining operations.