Abstract: A gripper device (24) for attachment to the inside of a tube (12) has a shaft member (26) including an upper tapered portion (30) surrounded by a generally cylindrical sleeve member (34) having at least two holes (38) opposite the tapered portion of the shaft. The sleeve outer diameter is slightly less than the inner diameter of the tube targeted for attachment. A spring (32) is connected between the shaft member and the sleeve member, for biasing the tapered shaft downwardly relative to the sleeve. A round bearing or hard ball (36) is located in each hole such that downward motion of the shaft relative to the sleeve urges the balls outwardly to protrude from the sleeve surface against the tube wall. The device is installed by pushing on stem (28) at the lower end of the shaft member to insert the device into the tube. A flange (44) is formed at the lower end of the sleeve to limit the sleeve insertion into the tube.