Abstract: A hand grip strengthener includes two operation arms, a strength adjustment assembly, a scale display element having a plurality of resistance level scales, and an indication element, the strength adjustment assembly includes a spring element, a spring driving element, and an adjustment control element, when the adjustment control element is operated by the user, the spring driving element is driven to move, so as to drive the spring element to move to adjust the resistance force applied to the relative movement between the two operation arms, the indication element is arranged to move along with the movement of the spring driving element, so as to be selectively aligned with the plurality of resistance level scales.

Abstract: A hand grip ring including a gripper ring body which includes a first gripping portion group including two gripping portions and a second gripping portion group including two gripping portions, wherein the two gripping portions of at least one of the first gripping portion group and the second gripping group have concave grooves at an inner side thereof respectively to guide deformation of the two gripping portions, wherein the first gripping portion group and the second gripping portion group have different elastic characteristics.

Abstract: An ergonomic hand grip strengthener includes a front operation handle for ergonomic placement of an index finger, a middle finger, a ring finger and a pinky finger of the holding hand of the user, a rear operation handle for abutting against a thumb and a palm of the holding hand of the user, and a strength adjustment assembly for adjusting a resistance applied to approaching movement between the front operation handle and the rear operation handle.