Wahl Diamond Edge Lithium-Ion Cordless Electric Beard Trimmer Kit, Men, 12pc, Black - 9886-600. The diamond edge is great for that ultra-close cutting. It features our black diamond finish on our stainless steel blades allowing them to cut closer, smoother, and cooler. Have the convenience of a cordless trimmer with up to 6 hours of run time on a single charge. You have unlimited options for styles with the 9 different cutting lengths.