Fine tuning of shock piston sizes has always been a tuning tool for the pro's. Now with this new tool from core rc its a simple task for any racer. This hand drill comes included with 8 different drill bits 1. 1mm, 1. 2mm, 1. 3mm, 1. 4mm, 1. 5mm, 1. 6mm, 1. 7mm and 1. 8mm.   2 double ended chucks are included allowing for drill sizes between 0 to 2. 9mm, for other simple hand drilling uses