This is not surprising. Each conga manufacturer has different diameters and you have to find the correct head for each drum. The numbers, meaning the head diameter measurements, are not consistent ... like you'd think.
If Remo told you which drumhead would fit the LP Aspire congas, that's what you need to go with.
Suggestion: If you are still concerned, take the current heads off your LP Aspire congas and bring them with you when you travel to the USA. This way you can size up what you need based on what you've got.
When measuring, you'll want to measure edge to edge of the drum itself, NOT the outer rim.
Each brand/model of conga has a slightly different measurement because of the thickness of the shell, the conga rim, etc.