i think syncwrap would be a better fit for K81dj.... the width of the cord is about 3.5mm and thickness is 2 mm....so... i think smartwarp will not do a good job.... not very sure but yesterday i DIY a smartwarp by myself... haha... using a plastic part(pp) about 3mm thick and saw it into shape, drill hole... mmnn.. works fine except the outlook not so fantastic....