A surgical tool can include a main unit and a first rigid sheath. The main unit includes an inner tube that is received within an outer tube. The first rigid sheath removably receives the main unit and connects to the main unit via a coupling between a first connector portion of the main unit and a second connector portion of the rigid sheath. The first rigid sheath can be completely removed from the main unit when the first connector portion is decoupled from the second connector portion. A different rigid sheath having a different shape from the shape of the first rigid sheath can then be removably attached to the main unit instead of the first rigid sheath. A surgical tool kit includes a plurality of rigid sheaths having different shapes and having the ability to be removably attached to the main unit.