Abstract: A repeatable use valve in a tennis ball that uses a common sports ball inflation needle inserted into and through the valve to increase or decrease the pressure inside the ball. The increase or decrease in pressure will cause the ball to have respectively higher or lower bounce. The valve can be installed in new tennis balls at the time of manufacture. The valve can also be installed in used tennis balls, including used tennis balls that have lost some or all of their original factory pressure.

Abstract: A collapsible container has a substantially rectangular base and four substantially trapezoidal walls. The short parallel sides of the trapezoidal walls are foldably joined to a perimeter of the base and the non-parallel sides are foldably joined end-to-end. The lengthwise walls are foldably divided into three segments along lines extending from approximately a corner of the base at approximately a 45 degree angle toward approximately a center of their long parallel sides. The long parallel sides of the walls form an open mouth of the container larger than the base when the container is in an expanded condition. The base, the widthwise walls and the segments of the lengthwise walls are substantially parallel when the container is in a collapsed condition.