They are lightweight, but firm (when I tried to squeeze the bottle, I couldn't deform it).

I opened the bottles by holding down the cap with my palm and rotating counterclockwise until the pump springs up. To close, I press the cap down and rotate clockwise. I find it easier to close the pump spray than to open it.

In the closed position, the bottles measure 6-inches tall.

In the open position (with the pump rotated counterclockwise to spring up), the bottles measure 6-3/4 inches tall.

After removing the entire cap, I measured the opening of the bottle to be 1-inch in circumference.