Abstract: A downhole tool that comprises an outer housing with an uphole end, a downhole end and an inner surface therebetween. The inner surface defines an interior space with a first inner-diameter and a recess with a larger second inner-diameter. The downhole tool also comprises a sleeve that is positionable within the recess of the outer housing. The sleeve comprises a ramp with a larger inner diameter towards an uphole end. The tool also comprises a seat that is positionable within the sleeve. The seat defines at least one plateau section that is configured to receive and support an equatorial portion of a ball, wherein when a pressure force is applied to the ball and seat, the ball and the seat slide along the ramp and a compressive force is applied to the equatorial portion of the ball.