I really feel you on this, it can be so stressful trying to figure out compatibility before you commit to buying. I am not 100% sure about the Ritsee A7 specifically, so I would not want to give you the wrong info lah. Your best bet is to reach out to the Capella Singapore official page or pop by a baby fair where they usually have staff who can check on the spot for you. Sometimes the brand's Instagram or Facebook comments section also has other parents who asked the same thing and got an answer directly from the seller.