WDM Bi-Directional SFP Module Supports WDM Bi-Directional technology, using a single strand of fiber, cost saving Paired with TL-SM321B or CM112CM Compatible with T3700 series, T2700 series, T2600 series, T2500 series, T1700 series, T1600 series, T1500 series, 2/3/5 series switches and MC220L