| In millions, except per share items | Dec-31-22 | Dec-05-22 | Dec-31-21 | Dec-05-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 |
| | 10-K | 8-K | 10-K | 8-K | 10-K | S-1/A | S-1/A |
| Cash flows from operating activities | | | | | | | |
| Net loss | | | | | | -25.9 | -14.3 |
| |
| Adjustments to reconcile net loss to net cash used in operating activities: | | | | | | | |
| Stock-based compensation expense | | | | | | 0.1 | 0.1 |
| Provision for credit losses | | | | | | 0.0 | 0.1 |
| Provision for excess and obsolete inventories | | | | | | 0.0 | |
| Loss on disposal of property and equipment | | | | | | 0.0 | |
| Changes in operating assets and liabilities: | | | | | | | |
| Accounts receivable | | | | | | -2.3 | -1.4 |
| Inventory | | | | | | -1.8 | -0.2 |
| Prepaid expenses and other current assets | | | | | | 0.2 | -0.6 |
| Other noncurrent assets | | | | | | -0.1 | 0.0 |
| Accounts payable | | | | | | 0.2 | 1.0 |
| Accrued compensation | 1.4 | | 1.9 | | 1.9 | | |
| Accrued and other current liabilities | | | | | | 1.5 | 0.5 |
| Other noncurrent liabilities | | | | | | 0.2 | 0.0 |
| Net cash used in operating activities | -76.0 | | -52.5 | | -32.2 | -25.0 | -14.5 |
| |
| Cash flows from investing activities | | | | | | | |
| Purchases of property and equipment | 1.0 | | 0.8 | | 1.0 | | |
| Net cash used in investing activities | -1.0 | | -0.8 | | -1.0 | -0.7 | -0.6 |
| |
| Cash flows from financing activities | | | | | | | |
| Proceeds from exercise of common stock options | 0.6 | | 0.4 | | 0.0 | | |
| Net cash provided by financing activities | 1.2 | | 252.5 | | 73.4 | 42.7 | 12.2 |
| |
| Supplemental disclosure of cash flow information | | | | | | | |
| Cash paid for interest | 3.3 | | 3.1 | | 1.3 | 1.1 | |
| |
| Supplemental noncash disclosure | | | | | | | |
| Acquisition of property and equipment included in accounts payable and accrued liabilities | 0.1 | | 0.2 | | 0.0 | | |