- This piston ring set is an oversize 0.50 with a bore diameter of 78.50 mm, designed to restore engine performance after wear. - Compatibility: specifically for Kubota engines, suitable for D1105 and V1505 models. - Reference numbers: 16292 and 21090 for ordering and verification. - Key benefits: restores compression by renewing worn rings, improves oil control to help reduce consumption, and is manufactured to align with OEM tolerances for reliable, long-lasting performance. - Why you need it: when bore wear compromises power and efficiency, this oversize set lets you rebuild to proper spec without a full engine replacement. - Use scenarios: 1) Overhauling a Kubota D1105-powered tractor to reclaim original compression and fuel efficiency. 2) Rebuilding a V1505-based generator or compact loader engine to reduce oil consumption and smoking. 3) Mid-life engine restoration on Kubota machinery where bore wear requires oversize rings to restore performance. - Practical notes: install per the service manual and verify bore size before use to ensure correct oversize fit and sealing.