For detailed specifications click on the chemistry :-

OEM Number	W & W Number	Specifications	Price	Qty
NTN8098B	WC-057D1-8098B	6 v @ 650mAh     NiCD	$65.00
NTN8100	WC-057D-8100A	6 v @ 1250mAh     NiCD	$52.50
NTN8100A	HC-057D2-8100A(S)	6 v @ 2000mAh     NiMH	$60.00
NTN8521A	HC-057D3-8521A	6 v @ 900mAh     NiMH	$65.00