GDC20-22(4.0S) 
Efficient punching without hurting hands
No hand injuries 3 anti-screwing hand protection 
No cracking 360 steady speed tiles 
Durable Battery Intelligent lithium system

GDC20-24(4.0S) 
Faster hole punching, no hand injury 
(30% more efficient in punching large holes)
Fast punching 4600 times/minute high-frequency hammering 
No hand injury 3 anti-twisting hand protection 
No cracking 360 steady speed tiling