Thank you for visiting Lit Systems, Inc. Click on the topic of your interest and the information will appear below the list. obstruction lighting maintenance We are fully factory trained and certified to work on every model of strobe currently in service. We stock a large inventory of parts for all dual mode strobes and most older white only strobes and incandescent systems. We offer fixed contract and per occurrence pricing. Contract pricing provides annual maintenance with unlimited site visits for a single annual rate. This allows for very accurate budgeting of system-wide maintenance costs with the only variable being parts usage. Per occurrence guarantees that you get the problem fixed for a single pre-determined rate even if we have to return to the site for a missing part for instance.