Specs: Height (H)*Width(W)*Thickness(T)

H*W*T=42*31*8cm   Max length:2-3m, Free 3 pads
H*W*T=42*31*12cm   Max length:4-5m, Free 6 pads
H*W*T=42*31*18cm   Max length:7-8m, Free 9 pads