This product is during the event, buy 2+ get 15% discount.
Just over $17.65 each in the 2x pack option.
Special note: This item supports charging to 4.35 V, so you can get more capacity and fly time (only for 1550mah 4s 100c)
Spec of ovonic 1550mah 4s:
Brand : Ovonic
Chemistry : Li-polymer
Length(dev.5mm) : 73mm
Width(dev.2mm) : 35mm
Height(dev.2mm) : 38mm
Capacity : 1550mAh
Voltage : 14.8V
Cell Number : 4S1P
Discharge Rate : 100C
Max Burst Discharge Rate : 200C
Net Weight(dev.20g) : 187g
Connector Type :XT60 Plug
Balance Connector Type : JST-XH
only has 1, 2,4,6 pack options. all not available apart from 4 pack. (unless i'm reading it wrong)