is brand name made for walmart made in china  model# is hb-135A used
for  pumping up air mattress has 12 volt lighter connection only. i
want to buy coverter to convert 110 ac to 12 volt dc so i can pump it
up in my apt. neither box instructions or pump indicates amperage
wattage etc. just 12 v d.c. i need to find out the amperage of the
pump. also when i disconnect pump air rushes out have u ant info on a
air pump for air mattress that has automatic shut off valve to prevent
leakage when pump is disconnected from aperture