Powerful watch case machin with handy handle. This new opener & closer is designed expecially for all water resistant screwback oyster cases. It accurately interlocks with the knurled deges of casbacks. It will not slip or damage casebacks. This sturdy frame fits any bench vise. It includes a centering pin which allows use in conjunction with the L-G "Master Case Opener" to open screw-on backs. This adjustable case holder accommodates all case sizes.