Stockholder's Equity | Stockholder's Equity (a) Stock Equity and Incentive Plan The Company recognizes stock-based compensation in accordance with the provisions of ASC Topic 718, Compensation-Stock Compensation . Stock-based compensation expense was $1,031 and $899, excluding $11 and $13 of compensation charges related to our Amended and Restated 1996 Employee Stock Purchase Plan, or the ESPP, for the three months ended September 30, 2021 and 2020, respectively, and $2,988 and $2,430, excluding $41 and $29 of compensation charges related to ESPP, for the nine months ended September 30, 2021 and 2020, respectively. As of September 30, 2021, there was $4,045 of total unrecognized compensation expense related to stock options, which is expected to be recognized over a weighted-average period of 2.62 years. As of September 30, 2021, there was $4,469 of total unrecognized compensation expense related to restricted stock awards, which is expected to be recognized over a weighted-average period of 2.4 years. Stock Options During the three months ended September 30, 2021, the Company issued 18 shares of common stock upon the exercise of stock options and received $143 as payment for the exercise price. No shares were surrendered to the Company to satisfy minimum tax withholding obligations. Additionally, during the three months ended September 30, 2021, no stock options were granted and 48 stock options expired, were canceled or were forfeited. During the nine months ended September 30, 2021, the Company issued 263 shares of common stock upon the exercise of stock options and received $2,615 as payment for the exercise price. No shares were surrendered to the Company to satisfy minimum tax withholding obligations. Additionally, during the nine months ended September 30, 2021, 496 stock options were granted and 126 stock options expired, were canceled or were forfeited. During the nine months ended September 30, 2020, 654 stock options were granted. The Company has estimated the fair value of each option grant on the date of grant using the Black-Scholes option-pricing model. The weighted average assumptions utilized to determine the fair value of options granted during the nine months ended September 30, 2021 and 2020 are as follows: Nine Months Ended September 30, 2021 2020 Risk-free interest rate 0.92 % 0.21 % Expected volatility 44.98 % 44.03 % Expected life (in years) 4.28 4.29 Dividend yield 0 % 0 % As of September 30, 2021, there were 2,142 options outstanding with a weighted average exercise price of $9.92 per share and 846 options exercisable with a weighted average exercise price of $9.33 per share. Restricted Stock During the three months ended September 30, 2021, 60 shares of restricted stock were granted with a weighted average grant date fair value of $11.00 per share and 17 shares of restricted stock were forfeited. Additionally, during the three months ended September 30, 2021, 68 shares of restricted stock vested, of which no shares of common stock were surrendered to the Company as payment by employees in lieu of cash to satisfy minimum tax withholding obligations in connection with the vesting of restricted stock. During the nine months ended September 30, 2021, 217 shares of restricted stock were granted with a weighted average grant date fair value of $12.23 per share and 37 shares of restricted stock were forfeited. Additionally, during the nine months ended September 30, 2021, 228 shares of restricted stock vested, of which no shares of common stock were surrendered to the Company as payment by employees in lieu of cash to satisfy minimum tax withholding obligations in connection with the vesting of restricted stock. As of September 30, 2021, there were 509 shares of restricted stock outstanding that were still subject to service-based vesting conditions. As of September 30, 2021, the Company had no unvested outstanding options and no outstanding shares of restricted stock that were subject to performance-based or market-based vesting conditions. (b) Employee Stock Purchase Plan The Company's ESPP affords eligible employees the right to purchase common stock, via payroll deductions, through various offering periods at a purchase price equal to 85% of the fair market value of the common stock on the first or last day of the offering period, whichever is lower. During the three and nine months ended September 30, 2021, 26 shares were issued under the ESPP plan. During the three and nine months ended September 30, 2020, 0 and 20 shares were issued under the ESPP plan, respectively. The Company recorded compensation charges related to the ESPP of $11 and $13 for the three months ended September 30, 2021 and 2020, respectively, and $41 and $29 for the nine months ended September 30, 2021 and 2020, respectively. (c) Stock-Based Compensation Expense The following table presents stock-based compensation expense, including under the ESPP, in the Company's consolidated statements of operations for the three and nine months ended September 30, 2021 and 2020: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Cost of product sales $ 78 $ 41 $ 194 $ 115 Cost of service sales 3 — 8 — Research and development 150 118 491 408 Sales, marketing and support 239 163 664 456 General and administrative 572 590 1,672 1,480 $ 1,042 $ 912 $ 3,029 $ 2,459 (d) Accumulated Other Comprehensive Income (Loss) (AOCI) Comprehensive income (loss) includes net income (loss) and unrealized gains and losses from foreign currency translation. The components of the Company’s comprehensive income (loss) and the effect on earnings for the periods presented are detailed in the accompanying consolidated statements of comprehensive income (loss). The balances for the three months ended September 30, 2021 and 2020 are as follows: Foreign Currency Translation Total Accumulated Other Comprehensive Loss Balance, June 30, 2021 $ (2,968) $ (2,968) Other comprehensive loss (370) (370) Net other comprehensive loss (370) (370) Balance, September 30, 2021 $ (3,338) $ (3,338) Foreign Currency Translation Unrealized Loss on Available for Sale Marketable Securities Total Accumulated Other Comprehensive Loss Balance, June 30, 2020 $ (5,377) $ — $ (5,377) Other comprehensive income (loss) 1,103 (1) 1,102 Net other comprehensive income (loss) 1,103 (1) 1,102 Balance, September 30, 2020 $ (4,274) $ (1) $ (4,275) The balances for the nine months ended September 30, 2021 and 2020 are as follows: Foreign Currency Translation Total Accumulated Other Comprehensive Loss Balance, December 31, 2020 $ (3,232) $ (3,232) Other comprehensive loss (106) (106) Net other comprehensive loss (106) (106) Balance, September 30, 2021 $ (3,338) $ (3,338) Foreign Currency Translation Unrealized Loss on Available for Sale Marketable Securities Total Accumulated Other Comprehensive Loss Balance, December 31, 2019 $ (2,767) $ — $ (2,767) Other comprehensive loss (1,507) (1) (1,508) Net other comprehensive loss (1,507) (1) (1,508) Balance, September 30, 2020 $ (4,274) $ (1) $ (4,275) |