This engineering drawing shows various components needed to support tools at the end of the arm on NASA's Curiosity rover, including: calibration targets for helping instruments set their baseline levels; spare bits for the rover's drill; a sample "playground" that gives the rover a place to drop off processed samples for observation by the APXS and MAHLI instruments; three inlet covers, which protect the SAM and CheMin instruments from atmospheric dust; and a set of five "organic check material" canisters, which provide a known chemical makeup blank that can be drilled and provided to SAM as a calibration material.