Using a Cheap Amazon Masonry Hole Saw: https://youtu.be/Vam4XEAkyDU
Hanperal 65mm SDS Plus Shank Hole Saw Cutter Concrete Cement Stone Wall Drill Bit (Amazon Affiliate)
US: https://amzn.to/2KKDPex
UK: https://amzn.to/2NqfxZI
CA: https://amzn.to/383mNT0
AU: https://amzn.to/2Zwt8DX
5/16″ SDS bit long (Amazon Affiliate)
US: https://amzn.to/2Z6wafQ
UK: https://amzn.to/2NrdnJ1
CA: https://amzn.to/35Q1S4s
1/4″ SDS bits (Amazon Affiliate)
US: https://amzn.to/31KpaHj
UK: https://amzn.to/2tYdzsB
CA: https://amzn.to/2ToLS6W