100mm holes

[a-z electrics]

Hi all,
Thinking of getting a drill for extractor fan vent holes thru walls - have used multi holes in circular pattern b4 now for the odd one or two Ive done but seem to be getting more of these, always been 100mm dia so far - assume sds mains is best way, is it worth getting a set? any particular make and sizes?
Cheers and thanks for replies...

 

[a-z electrics]

sorry thats a core drill I need - I have a bosch mains sdsplus drill already..

 

[RyanCheetham]

I have a cheap erbauer set i got from screwfix. Works a treat

 

[drew35]

I have an Erbauer one size fits all 117mm! And I only use it in my SDS drill, and its not failed me yet! Even on the hardest lintel....................