Attaches any 4x4 FiberRunner? Fitting or Channel to the 2x2 Fiber-Duct? Channel, S2X2BL6 or E2X2BL6 or 2x2 FiberRunner? Channel, HS2X2BL6 or H2X2BL6. Note: Attachment to 2x2 FiberRunner? Channel requires a QuikLock? Coupler FBC2X2BL. Includes solid cover.