The Company maintains a stock incentive plan that permits the granting of incentive stock options or nonqualified stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance awards, and other stock-based awards. The equity-based awards for employees generally vest over a four-year period. For initial equity-based awards granted to employees, the first vest is generally a one-year cliff vest, followed by monthly vesting for the final three years. Thereafter, annual equity-based awards granted to employees typically vest monthly over the four-year vest term, except for restricted stock units which vest annually over a four-year period. The initial equity-based awards granted to the Company’s non-employee, independent directors upon appointment to the board of directors vest over a three-year period, with the first vest being a one-year cliff, followed by monthly vesting over the remaining two years. Thereafter, annual equity-based awards granted to the Company’s non-employee, independent directors cliff vest after one year from the date of grant.

The following table summarizes stock option activity for the six months ended June 30, 2026 (in thousands, except share and per share data):


	Number of Shares			Weighted Average Exercise Price per Share		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2026		5,271,889		$	5.70		6.71	$	6,940
Granted		1,349,000		$	2.44
Exercised		(84,236	)	$	2.12
Forfeited		(80,273	)	$	4.27
Expired		(26,631	)	$	3.58
Outstanding at June 30, 2026		6,429,749		$	3.34		6.91	$	18,115
Vested and expected to vest at June 30, 2026		6,145,067		$	3.47		7.11	$	16,627
Exercisable at June 30, 2026		3,748,632		$	2.84		5.91	$	11,673

The weighted average assumptions used in the Black-Scholes pricing model for stock options granted during the three and six months ended June 30, 2026 and 2025, were as follows:


	For the Three Months Ended June 30,						For the Six Months Ended June 30,
	2026			2025			2026			2025
Estimated dividend yield		-	%		-	%		-	%		-	%
Weighted-average expected stock price volatility		35.97	%		37.16	%		36.97	%		36.05	%
Weighted-average risk-free interest rate		4.19	%		3.99	%		3.80	%		4.33	%
Expected average term of options (in years)		5.55			5.53			6.16			6.16
Weighted-average fair value of common stock	$	5.30		$	5.41		$	2.44		$	7.89
Weighted-average fair value per option	$	2.15		$	2.22		$	1.03		$	3.42

The following table summarizes restricted stock unit activity for the six months ended June 30, 2026 (in thousands, except share and per share data):


	Number of Shares			Weighted Average Grant Date Fair Value per Share		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2026		45,073		$	5.41		0.66	$	171
Granted		—		$	—
Vested		(22,538	)	$	5.41
Forfeited		—		$	—
Outstanding at June 30, 2026		22,535		$	5.41		0.66	$	128
Vested and expected to vest at June 30, 2026		22,535		$	5.41		0.66	$	128

The Company maintains an employee stock purchase plan (ESPP) that authorizes the issuance of shares of common stock pursuant to purchase rights granted to eligible employees. Unless otherwise determined by the Company’s board of directors, shares of the Company’s common stock will be purchased for the accounts of employees participating in the Company’s ESPP at a price per share equal to the lesser of (i) 85% of the fair market value of a share of the Company’s common stock on the first day of an offering; or (ii) 85% of the fair market value of a share of the Company’s common stock on the date of purchase. Offering periods are generally six months long; offering periods begin on June 1 and December 1 of each year. The Company issued 13,719 shares of common stock under the ESPP during the three and six months ended June 30, 2026 and 11,518 shares of common stock under the ESPP during the three and six months ended June 30, 2025.

Stock-based compensation expense included in the accompanying condensed financial statements was as follows (in thousands):


	For the Three Months Ended June 30,				For the Six Months Ended June 30,
	2026		2025		2026		2025
Cost of sales	$	15	$	27	$	35	$	56
Research and development		8		7		17		(1	)
Sales and marketing		85		58		177		105
General and administrative		514		858		1,088		1,642
Total stock-based compensation expense	$	622	$	950	$	1,317	$	1,802

Stock-based compensation expense related to stock options was $0.6 million and $1.2 million for the three and six months ended June 30, 2026, respectively, and $0.9 million and $1.7 million for the three and six months ended June 30, 2025, respectively. Unrecognized compensation expense related to stock options was $4.6 million at June 30, 2026, which is expected to be recognized as expense over the weighted-average period of 2.76 years.

Stock-based compensation expense related to restricted stock units was not significant for each of the three months ended June 30, 2026 and 2025, and was $0.1 million for each of the six months ended June 30, 2026 and 2025. Unrecognized compensation expense related to restricted stock units was $0.1 million at June 30, 2026, which is expected to be recognized as expense over the weighted-average period of 0.66 years.

Stock-based compensation expense related to the ESPP was not significant for either the three and six months ended June 30, 2026 and 2025. Total compensation expense related to the ESPP not yet recognized was not significant at June 30, 2026. As of June 30, 2026, an insignificant amount has been withheld on behalf of employees for future purchases under the ESPP.