Series 150 Releasing and Circulating
Overshot is an external fishing tool for engage,
pack off and retrieve tubular fish, especially for fishing
drill collar and drill pipe. The grapple of the overshot
can be designed for different sizes of fish, so one
overshot can be dressed with different size of
grapple components for fishing different sizes of fish.

Construction
TOPTECH Series 150 Overshot consists of three
outside parts: Top Sub, Bowl, and Standard Guide.
The Basic Overshot may be dressed with either of
two sets of internal parts, if the fish diameter is near
the maximum catch of the Overshot, a Spiral Grapple,
Spiral Grapple Control, and Type “A” Packer are
used. If the fish diameter is considerably below
maximum catch size (½” or more) a Basket Grapple and
a Mill Control Packer are used.