The A-C7 Mining laser, is a upgraded version of the P-7 which is a upgrade of the Mining Laser these three lasers can be made crafted at the Tinkering Table
The mining lasers all use energy, but not a lot of it.
The A-C7 Mines out approximately 6x4 blocks at a time, that includes background walls as well, but only if a front block is mined at the same time. I found it difficult to not destroy everything when mining out trees and stuff. So do be careful when using this tool :)
The A-C7 is crafted out of
P-7 x1
Manipulator Module x1
Telebrium bars x2