The On-Off Seal Unit is a short, compact, overshot type receptacle with a Jay, which engages automatically and releases with a one quarter turn left hand rotation. This tool provides a means of disconnecting and re-connecting the tubing string without unseating the packer. A profile in the seal mandrel provides a means of blanking off the zone below the packer with a Wireline Retrievable Plug. After remedial work has been completed, the tubing may be re-engaged at the On-Off Seal Unit and the Tubing Plug pulled by wireline to place the well on production. The standard overshot has two bonded seals which allows for multiple disconnects and re-connects. Both 6K and 10K pressure ratings are available.