Sorry I can't remember (or find) the colleague who recommended these.
I have tried one in my Pioneer sub (admittedly on 458 Mhz where noise and glitches are generally no problem) on several occasions and it works fine. It may have changed my generally negative view of noise from switch mode power supplies. (I have ordered another couple.)

Sellers Specification:
Brand new
Size: approx. 42*24*11mm
Output Voltage: 5V or 6V (Changeable with an output-voltage select switch)
Continuous Output Current: 3 Amps
Input: 5.5V-26V (2-6 cells lithium battery pack or 5-18 cells NiMh /NiCd battery)
Fine workmanship and good performance.
Easy to use.
Long service life.
Package included:
1 x 3A RC UBEC Switch
» Servo Depth controller
» WW2 mini sub build
» Waterproof servos
» Robbe Seawolf V2
» BEC - Switch mode
» Cheap Arduino Auto leveler
» Pump for bladder system
» Wireless charging