Up for your consideration is a ver nice HILTI Diamond Core Bit DD-C 16/300 T2 16mm 5/8" 12" Deep 336898. Compatible with a HILTI DD EC-1 core drill. Make sure to look at the other HILTI Diamond Core Bit DD-C 18/300 T2 I currently have listed. Please ask any questions you might have. We use both Fed Ex and UPS and we will use which ever one gets your package out and to you the soonest. The price will remain the same, but we always reimburse if over paid.