@wangling Perhaps you are referring to a "Drive Hand Held Spray Nebulizer"?(https://www.healthproductsforyou.com/p-drive-lexan-plastic-pocket-nebulizer.html)
or the "Drive Power Neb Extra Portable Nebulizer"?
(https://www.vitalitymedical.com/drive-medical-power-neb-ultra-compressor-nebulizer.html)
The first is a handheld bulb spray activated device, commonly used by people with no access to electricity. I would only consider it to be a backup device myself as I think it would be very difficult to deliver a even, fine mist squeezing a bulb. My arthritic hands and wrists would definitely not like it.
The second is a small table top compressor-type nebulizer. The literature describes it as portable, but at 3.2 pounds and without a battery option, I wouldn't call it that. It does have a 5 year warranty, and from the description, I would say it is comparable to the old standby Pari Vios that is also covered by Medicare.

Is this the first time you have been prescribed a nebulizer?
Sue