The Company had two and three customers that individually comprised 10% or more of net revenue for the three months ended December 31, 2014 and 2015, respectively, as follows:

			Three months ended December 31,
		2014			2015
Shandong Tangjun Electric Co., Ltd	$	*	*	$	2,436,471	44.29%
Pingxiang Anyuan Tourist Bus Co., Ltd		*	*		1,202,286	21.86%
Sichuan Pisen Electronics Co., Ltd		1,440,041	46.77%		947,653	17.23%
Guangdong Pisen Electronics Co., Ltd.		1,379,626	44.81%		*

The Company had two and three customers that individually comprised 10% or more of accounts receivable as of September 30, 2015 and December 31, 2015, respectively, as follows:

		September 30,			December 31,
		2015			2015
Shandong Tangjun Electric Co., Ltd	$	*	*	$	2,113,022	44.52%
Pingxiang Anyuan Tourist Bus Co., Ltd		*	*		1,306,657	27.53%
Sichuan Pisen Electronics Co., Ltd.		3,146,177	65.93%		553,255	11.66%
Guangdong Pisen Electronics Co., Ltd.		763,738	16.01%		*	*

For the three months ended December 31, 2014 and 2015, the Company purchased inventories of $1.7 million and $3.0 million from BAK Tianjin and nil and $5,344 from Shenzhen BAK, respectively. Also, the Company generated revenue of nil and $0.3 million from BAK Tianjin and $21,442 and $0.6 million from Shenzhen BAK for the three months ended December 31, 2014 and 2015, respectively.

Financial instruments that potentially subject the Company to a significant concentration of credit risk consist primarily of cash and cash equivalents and pledged deposits. As of September 30, 2015 and December 31, 2015, substantially all of the Company’s cash and cash equivalents and pledged deposits were held by major financial institutions located in the PRC, which management believes are of high credit quality.

For the credit risk related to trade accounts receivable, the Company performs ongoing credit evaluations of its customers and, if necessary, maintains reserves for potential credit losses. Historically, such losses have been within management’s expectations.