New Balance Men's MR1400 100% Synthetic and mesh Rubber sole Weight: 190 Grams REV-Lite - Innovative midsole unit which maintains a minimalist profile whilst still offering the same compression set and responsive cushioning properties. Blown Rubber Outsole - Lightweight rubber providing cushioning Open Mesh No-Sew Upper - Provides lightweight comfort, support and breathability with a no-sew construction which reduces weight and improves comfort. NBJ Athletic Last - Racing last which provides a more secure fit for the runner, ideal for long-distances.