HyperX Beast (T3) - 16GB Kit* (4x4GB) - DDR3 2400MHz CL11 Intel XMP DIMM
Part Number: KHX24C11T3K4/16X
is compatible with Asrock Z87 extreme 4 motherboard?
Yes, the memory is compatible and it will work fine. But I'd recommend you to go with 2 x 8GB rather than 4 x 4GB.
# - 2x8GB would run with less stress to MC (memory controller) while 4 modules will increase the stress.
# - Moreover, your motherboard and chipset does not support Quad Channel memory architecture so installing 4 modules will still run at Dual channel.
# - Also if you go with 2 x 8GB modules you will have more slots for future upgrade.
But you can decide about this, but if I were you that would be my choice i.e, 2x8GB. The kit looks fine, and DDR3-2400MHz is a good speed but make sure you have an unlocked CPU - Intel "k" model.
Hope i've answered your question, lemme knw if you need any info. Cheers, mate