it's possible that these are two different variations of an electric bike or scooter model offered by a manufacturer. The key difference between the two models might be related to their frame design.

"Step-Through" typically refers to a frame design in which the top tube of the bike's frame is lowered or curved to allow for easier mounting and dismounting, especially for riders wearing dresses or skirts. This design is particularly convenient for riders who may have difficulty swinging a leg over a higher top tube.

On the other hand, a non-step-through Sinch Step-Through Foldable Ebike or standard frame design might have a more traditional frame with a horizontal top tube.

To learn more about the specific differences between the "Sinch" and the "Sinch Step-Through," I recommend checking the manufacturer's official website, product documentation, or reaching out to the manufacturer or retailer directly. They should be able to provide you with detailed specifications and features of each model.