That`s known as a `Scalloped` edge .... it`s not really widely-used now ...was popular some time back...I`ve worn one [Topper] .....one big problem is you`re going to have Glue / tape ` exposed` where the gaps are..... it`s just too ` fiddly` to be dealing with.... I can see no advantage to having this design..... a regular curved front, and a graduated hairline works just fine.... my 2 -cents worth !