This report describes the results of a pneumatic pressure standards key comparison among eleven SIM National Metrology Institutes in order to determine their degree of equivalence in the pressure range from 0.6 MPa to 7 MPa in gauge mode. The pilot laboratory was the Centro Nacional de Metrología (CENAM, Mexico). All participating institutes used pneumatic pressure balances as their pressure standard. The transfer standard was a complete system including a pressure balance with a free-deformational pistoncylinder assembly and a set of masses. Eleven participants completed their measurements, although, only ten laboratories reported the pressure-dependent effective areas of the transfer standard at specified pressures with the associated uncertainties; NRC/Canada withdrew the comparison by not sending their measurements. NIST, USA, provided the reference values to link the results to the CCM.P-K1.c comparison of the ten laboratories that sent their results. To evaluate the compatibility of results of the participants their relative deviations from those obtained by NIST results were analysed. The results of 7 participating NMIs agree with NIST reference values within their expanded uncertainties (k=2).