This is the exact one he puts a sticker on and sells for $40:

Adjustable AC/DC Switching Power Adapter Variable Voltage DC5525 Power Supply 4-24V 4V 9V 12v 14V 15V 18V 24V 2A 48W Speed Control Volt for Electric Fan Drill Motor Speed Controller Arduino https://www.amazon.com/dp/B07N2FN18R/ref=cm_sw_r_apan_glt_fabc_K8E2QD46GJNKN897V1XN?_encoding=UTF8&psc=1