Review (1/5): Less than half of the specified size
The specified size of the stone is 4.3 x 2.8 x 1.4inch. The actual size is 3.5 x 2.125 x 1.0inch, only 44% of specification. This is way beyond any margin of error in the manufacturing process. You should also note the estimated delivery date. Although it says "prime free shipping," it took a week to arrive in first class mail.