MCR Safety Dyneema® Sleeves. Dyneema® is comparable to aramids and much better than traditional materials like leather, cotton, and nylon. Disperses heat four times faster than aramids, cotton and leather, ensuring that the gloves feel cool and comfortable. Dyneema® is able to bend and move in a very flexible way. Due to its high tenacity (strength) it is extremely resistant to tears which increases the life of Dyneema® products.