Corillas Neuter 20 inch 6 speed Folding Bike

is an Alloy Frame Folding bike, Wheel Size 20 inch, Frame Size 18 Inch with adjustable Seat post and 6 speed Shimano Transmission

AMIAO Alloy 6 speed 20 inch Folding bike

is an Alloy Frame Folding bike with Wheel Size 20 inch, Frame Size 18 Inch plus adjustable Seat post

Viking City Urban 20 Folding bike

The Viking Folding Bike is not really suitable for extreme trail riding, it’s on the heavy side. However,  models tend to be in the lower price range when compared to the likes of Brompton and Triton folding bikes.