Abstract: A hand exerciser includes a loop having a smooth outer periphery and a plurality of rings each having a hole so that the loop extends through the hole of each ring. An inner diameter of the hole of each ring is 1.5 times of an outer diameter of the loop so that the rings are rotatable relative to the loop. The user rotates the loop to keep the rotating rings maintained at a section and the vibration of the rings to the loop exercises the hand holding the loop.

Abstract: A hand exerciser includes a hollow sphere that has four openings and a cruciform member is supported in the sphere. Two handle disks and two massage disks are rotatably connected to four ends of the cruciform member and respectively engaged with the openings. A rod extends from a center of the cruciform member and a spring is mounted to the rod and a tube is rotatably mounted to the rod and biased by the spring. A weight is connected to a lateral rod extending from the tube. The eccentric force by the weight when the sphere is rotated applies a force to the hands holding the handle disks or the massage disks.