The measurement of the head of the Madan is: 4.5"H 2.5W
If your concern is because of the size of your Yorkie...I've had a customer w/a 2.5 lb Yorkie who was very happy w/the Madan.
The $1 additional is for the shipping charge for the 2nd brush, so if purchasing 2 brushes, the shipping total will be $3.75 (2.75 ~1st + 1 ~ 2nd). 3rd would also be an additional $1 & so on.
Please don't hesitate to ask any questions you may have.
Thank you! ~Jenny