Bad product and worse customer service.
Purchased 2 pairs of these suction cups. It never worked because one plastic part had multiple cracks. I changed messages with Customer Service for 2 weeks until I realized they are not willing to issue an RMA, nor a refund, just lies after more lies. I had to go through the credit card company to get a partial refund, just for a pair, the other one being purchased about 2 months before. I saved all the conversation with Vevor Customer Service, about 12 pages, in case somebody asked.