https://www.gearlinkoptic.com/products/sfp28-25g-copper-twinax-cable-xm-dac/ SFP28 Direct Attach Cables (25g dac) are compliant with SFF-8432 and SFF-8402 specifications. Various choices of wire gauge are available from 30 to 26 AWG with various choices of cable length (up to 5m). The SFP28 passive direct attach copper cable assemblies are high-performance, cost-effective I/O solutions for 25G Ethernet. SFP28 DAC copper cables allow hardware manufacturers to achieve high port density, configurability, and utilization at a very low direct attach copper cable sfp+ cost and reduced power budget of passive copper cable.