Hi,
would like to get advice from you guys.
I have cement slab roof type with crack and it leaks.
Saw some video for repair the crack which require to make is bigger before repair can be done.

I was wondering is that tool called as angle grinder?
If yes i need some recommendation on the basic type for me to cut the concrete.I am thinking of Bosch GWS 060 Angle Grinder.

Please advice.

Thank you.