Do you sleep easy knowing your jack is made in China?

What size lumber are you using to make these. 2x4s 2x6s what's the square dimension of one of these? Height? I have seen them in a lot of posts. I think they are a great idea. I would like to make some for my shop.

Mine are 2x4's and we're cut 14in pieces, so 14x14in and they are 16in high.