I use Remington HC4250. It's curved and has attachment to adjust cut
https://www.amazon.com/Remington-HC4250-Shortcut-Self-Haircut-Clippers/dp/B014SG66UO/ref=sr\_1\_7?crid=23HLQBWI397P1&keywords=Skull+clipper&qid=1688157903&sprefix=skull+clipper%2Caps%2C258&sr=8-7