Let me introduce the difference between the new and old models

The J series is the old model, the F series is the new model

The J series saw blade has manual adjustment of tension, and there is no fixed tension standard

The F series saw blade has automatic adjustment of tension, and a prompt sound will be emitted when tightened to the appropriate position

The J series upper wheel is embedded, so it is not so convenient to clean

The F series upper wheel is detachable, which is convenient to clean

The J series does not have anti-cutting protective gear

The F series has anti-cutting protective gear