We would like to share the details about K-4 here with you. Specification: Multi-row ceramic ball bearing system 3-D machined Titanium handle Blade Length：3.9" Blade Thickness：0.157" Overall Length：8.5" Hardness：60-61HRC Handle Material：6AL4V Titanium Blade Material：Bohler M390/Damasteel Inlay Material：Carbon fiber/Damasteel Weight：5.3 oz Locking：Frame Lock Blade finish：Satin finish/Black PVD coating/Damasteel Handle finish：Bead blast/Blue/Bronze/Black PVD coating Here are some photos of K-4. Reate Knives would like to talk a little bit about one important techniqueFreeze Edging Skill. As the final process for a blade, edging has a great effect on the performance of the knives, after all, the edge part is the main function area when using a knife. Normally, edging is operated on a high-speed running grinding wheel or grinding belt, which produces a very high temperature. Without a cooling system, the temperature on the edge goes up instantly to hundreds of centigrade, when it gets worse, it will burn and leave heat marks on the blade. Tempering or even annealing will happen on area of the edge where the temperature increasing instantly. It will harm the hardness and durability of the blade. Thats why some knives passing the hardness standard test but still easily get worn in actual use. Reate Knives are using the freeze edging technique. During grinding, the temperature on the edge is controlled in a certain level of degree, which helps keep the hardness after the heat treating. Therefore, the sharpness and durability of the blade are assured. This helps bring the performance of the material to the best. Thank you very much for your time. Reate Knives Team.