The Iso paddles from FINIS are strapless paddles designed to isolate specific muscle groups, develop proper hand position, and heighten stroke awareness. The FINIS Iso paddles are uniquely designed to create an imbalance in the catch phase of a stroke, which forces swimmers to apply more pressure on either side of the paddle in order to maintain a proper stroke. The variance encourages swimmers to pay increased attention to hand position in the water, keeping it level and consistent throughout the catch and pull of each stroke. Using the edge on the inside allows swimmers to isolate and engage the pectoral, bicep and deltoid muscles. Using the edge on the outside (grey on left, yellow on right) allows swimmers to isolate and engage the triceps and trapezius muscles (recommended for backstroke and freestyle). Using the edge on the inside (yellow on left, grey on right) allows swimmers to isolate and engage the pectoral, bicep and deltoid muscles (recommended for butterfly and breaststroke).