Extremely RARE !!!! Genuine...  Secondo Mona  S.p.A. . Aircraft fuel  Filler  cap with mounting concave adapter ring, .............., This is Ex-MoD parts stores items .   NEW in sealed bag, ,  N.S.N part no. 1560-15-061-5851 , . the red anodised cap is manufactured by Secondo Mona S.p.A. , this part number is SM2370 , the adapter fitting ring ( manufactured in Italy )  part number is SM2373, , original  labels clearly shown..... The overall dimensions are 130mm diameter ( this is the measurements of the adapter plate,  Please note This is concave and clearly shown in the photos, ( Aircrafts don't have many flat surfaces !!) ......... However this is by far the best quality filler cap you will find for your custom car build or custom motor bike builds, . ..... please view all of the pictures to ensure this is the correct size as we cannot accept returns once the item is removed from its original packaging ....... These are NEW and have never been removed from their packaging , . If you are unsure of anything please ask before buying , we are here to help with your enquiries , ..... Signed for delivery to UK including UK G.S.P. depots  for International buyers,  we have more than one available, .... This is a VERY RARE chance to buy a Genuine UNUSED Aircraft Filler cap with correct mounting adapter, .