Your current receiver shoud specify the power and size on the silver part that goes in your ear.
Widex V2 P1L Easywear Receiver For Rechargeable Moment Hearing Aids - Left Ear
Widex V2 M0R Easywear Receiver For Rechargeable Moment Hearing Aids - Right Ear
Phonak Roger X 02 champagne colour receiver for installing into hearing aids
ReSound SureFit 3 M&RIE Size 1 Left Side Receiver for ReSound ONE Hearing Aids
ReSound SureFit 3 M&RIE Size 1 Right Side Receiver for ReSound ONE Hearing Aids
Widex V.2 M Receivers For Moment Hearing Aids