The invention relates to a composition comprising -1,1,1,4,4,4-hexafluorobat-2-ene as a mixture with at least one hydrocarbon, hydrofinorocarbon or fluoroolefin compound having a boiling point less than or equal to \u221212\xb0 C. The echo filter is arranged between an input channel and an output channel. The staple cartridge may have an annular or linear configuration of retention slots. A mechanical coupling is thereby provided entirely within the casing of the chain hoist to transmit rotary motion from the rotary drive shaft directly to the position sensor. Polyurethane may be added to one or more selected portions of the dash insulator to reflect andor absorb sound.