This Qingdao Lisan company is very good at face engineering. They don't have a team to develop pumps at all. All pumps are 1: 1 cloned Glenford pumps, which are actually illegal and highly imitated. Their products claim to be imported pumps and motors, but in fact they are imitations. You bought an imitation at the expense of imports. It is worth mentioning that you are likely to be fooled. Their products will spend a lot of money on packaging and appearance, in order to make you look beautiful and not be considered as inferior products made in China. In fact, they don't know anything about technology, and probably don't even understand the principle of pumps. Don't believe me, I visited them and asked them some professional questions, which their "technicians" didn't know. I heard that the manager graduated from primary school.