10G SFP+ DAC (Direct-attach Cable) are made of twinax copper, it provide a cost-effective, environmental alternative to 10G optical SFP+ connection. It is assembled with two 10G SFP+ head which cannot be removed and the cable length is fixed. 10G SFP+ DAC is a better option for short-distance connections within racks and across the adjacent racks, with the advantage of high reliability and low power consumption, it is more and more popular in data centers and other 10G Ethernet application. AscentOptics could provide passive and active copper twinax cables. The 10G passive DAC cables can be up to 10 meters, and an active 10G SFP+ twinax copper cables could reach up to 15 meters.