The Gul Petrel 7 Seas Cap features Revofit 3D molded technology for optimum fit and comfort, delivering outstanding hydrodynamic performance. Made with 96g+ silicone, it's double the weight of average 2D 48g swimming caps, helping to reduce heat loss for extended comfort in the water. Key features include: easy to use, comfortable, and streamlined for ultimate performance. It is made from 100% 3D silicone. The Glow colour option includes ‘Firefly’ Technology, allowing the cap to glow in low light conditions, making it a great safety feature for open water swimming. It can also be worn under a Gul neoprene skull cap for added warmth.