QSFP+ optical ports of CE series switches must use QSFP+ (40GE) optical modules and cables.
When a 40GE optical port works in 4*10GE mode, it can use:
QSFP+ optical module and MPO-4*DLC or MPO-MPO-8*FC optical fiber
QSFP+ to 4*SFP+ high-speed cable
QSFP+ to 4*SFP+ AOC cable