I use this USB rechargeable pump on my Thermarest Mondo king pads and love it. Its small but powerful enough to get the job done. Switch the nozzle around and it deflates too.

https://www.amazon.com/dp/B07RZST1F3/ref=cm_sw_r_cp_apa_fabc_z5qbGbVECQP5N?_encoding=UTF8&psc=1