CemAir offers a web check-in service on their website, which allows passengers to check-in for their flight and select their seat from the comfort of their own home or office. To use the web check-in service, passengers will need to visit the CemAir website and enter their flight details, such as their booking reference or e-ticket number. They will then be able to select their seat, print their boarding pass, and check-in for their flight. It is usually available 24 hours before the departure of flight and close 1 hour before the departure. It is recommended to check with the airline's website or customer service for the most up-to-date information on the check-in process and deadlines.