This detail about specific kit incompatibility for the 0.4ohm should be included. (0.4Ω, 0.6Ω, 0.8Ω, 1.2Ω). Compatibility: Compatible withmost OXVA Xlim Kits (Xlim EZ, Xlim Pro, Xlim Pro 2, Xlim SE, Xlim SE 2, Xlim SQ, Xlim SQ Pro, Xlim Go, Xlim V2).