13X4 Lace Frontal Unit
The difference between a 13x4 and a 13x6 is how much more lace is going towards the back of the head. A 13x4 only goes back 4 inches while a 13x6 does back 2 more inches. The 13x6 will give a more natural look than the 13x4. The 13x4 will be cheaper than the 13x6 because of the fact it has more lace on it.
