X2 and XENPAK is an old version of 10G transceiver. It has been replaced by more compact devices providing the same functionality. Both X2 and XENPAK are SC connector, and have the same electrical interface as XENPAK (known as XAUI), X2 modules are smaller and consume less power than first generation XENPAK modules, but larger and consume more energy than the newer XFP and SFP+ transceiver. Optinet still can provide X2 and XENPAK modules, all modules support Digital Optical Monitoring (DOM) function. Some customers prefer to use X2 SR, LR, ER, ZR based on X2 to SFP+ converter module and SFP+ module. XENPAK SR, LR, ER, ZR, XENPAK to SFP+ converter module and SFP+ module.

Below listed is popular models: