The following sections and tables provide details of selected balance sheet items (in thousands):

	As of
	April 30, 2019		January 31, 2019
Finished goods	$	8,190	$	7,567
Raw materials		2,509		2,550
Total inventory	$	10,699	$	10,117

	As of
	April 30, 2019		January 31, 2019
Prepaid expenses	$	2,342	$	2,681
Deferred sales commissions, current		1,395		1,081
Deferred inventory costs		403		334
Other current assets		1,244		1,354
Total other current assets	$	5,384	$	5,450

Under Topic 606, the Company capitalizes a significant portion of its sales commission costs as an incremental cost of obtaining customer contracts and amortizes to sales and marketing expense over an expected benefit period of five years. During the three months ended April 30, 2019 and 2018, amortization expense for deferred sales commissions was $0.4 million and less than $0.1 million, respectively. To date, there have been no impairment losses related to the costs capitalized.

	As of
	April 30, 2019		January 31, 2019
Deferred sales commissions, non-current	$	4,292	$	3,387
Convertible note receivable, including interest income		1,348		1,300
Other non-current assets		841		692
Total other assets	$	6,481	$	5,379

In December 2018, the Company invested $1.3 million in cash to Global Telecomm Corporation (“GTC”), a small privately-held technology company, in exchange for an 18-month convertible promissory note, bearing interest at 10% annually. The principal and unpaid accrued interest on the promissory note will convert to shares of GTC common or preferred stock upon the occurrence of certain future events. As of April 30, 2019 and January 31, 2019, the Company did not hold any shares of GTC common or preferred stock. The Company has partnered with GTC on certain research and development efforts. The Company is required to consolidate the assets and liabilities of variable interest entities (“VIEs”) in which it is deemed to be the primary beneficiary. GTC is considered a VIE because, among other factors, it lacks sufficient equity to permit the entity to finance its activities without additional subordinated financial support from other parties. The Company’s convertible promissory note issued by GTC represents a variable interest. However, the Company does not participate in the day-to-day operating decisions or other decisions that would allow it to control GTC, and therefore, the Company is not considered the primary beneficiary and does not need to consolidate GTC’s financial statements in the Company’s financial statements. As of April 30, 2019 and January 31, 2019, the Company’s maximum exposure to loss was equal to the carrying value of its convertible note receivable and associated interest receivable. For all periods presented, the Company had no other variable interests in VIEs.

As a result of the Company’s investment, GTC is a related party of the Company. During the three months ended April 30, 2019, the Company procured certain raw material inventories from GTC that amounted to approximately $0.2 million. As of April 30, 2019 and January 31, 2019, the Company recorded prepaid inventory deposits to GTC of $0.3 million and zero, respectively, included in other current assets on the condensed consolidated balance sheet.

	As of
	April 30, 2019		January 31, 2019
Payroll and related expenses	$	4,467	$	7,926
Regulatory fees and taxes		5,225		5,645
Short-term operating lease liabilities ⁽¹⁾		1,836		—
Acquisition-related consideration		906		925
Other		4,645		4,552
Total accrued expenses	$	17,079	$	19,048

⁽¹⁾The Company adopted Topic 842, the new accounting standard for leasing arrangements on February 1, 2019. See Note 6: Operating Leases below.