Before the 6040 solar lights, other models had already been tried. Initially, they were quite good, but after a few months, they became increasingly dim, clouded over, or stopped working altogether. Therefore, this time the decision was made for a durable and reliable solution – even for winter. It's better to invest wisely once than to have to buy new solar lights every year.
Oh, and should the battery weaken after several years, it can be easily replaced with standard AA rechargeable batteries thanks to the convenient battery compartment – instead of throwing away the entire light.