Cylinder Kit 937 GS370 137 (38mm) 50182005A This cylinder kit is designed for compatibility with specified engine models.It includes a cylinder and piston set with a 38mm bore size.The kit is engineered for straightforward installation and consistent performance in applicable two-stroke engines.-machined components support and durability under standard use conditions. This is a non- replacement.Any reference to brand names or models is strictly for compatibility purposes.