Metal-end-cap (MEC) seals combine elastomer core with stainless or Inconel end caps to eliminate extrusion at differentials above 15,000 psi. Widely used in 15K and 20K wellhead systems, they provide long-term reliability in deepwater and unconventional land completions. https://globalsealstech.com/product-category/oil-gas-seals/api-6a-wellhead-equipment-seals/