6 Clip Plates For 6 Each 15-17Mm Tubes:Pack of 6 metal clip plates to accommodate up to 6 tubes with a diameter of 15-17mm. A maximum of 8 clip plates, 4 per side, may be attached to the Magnetic Platform for use with the Roto-Shake Genie, Enviro-Genie or Incubator-Genie. A maximum of 12 clip plates, 6 per side, may be attached to the Magnetic Platform for use with the Rotator Genie