Dr Dennis Gross Advanced Retinol And Ferulic Texture Renewal Serum Size: 7ml - Travel / Sample Size. This is a great way to try the product before purchasing the full-sized version. Or to take travelling! RRP: £76 for 30ml This is a new, unopened product. I received this as part of a free gift with a large purchase from an online beauty retailer. Please check out my other items as I have other beauty products for sale and would be happy to combine postage. Please check out my feedback for assurance that I’m a trusted seller.