Plumber is a compound sign: first, sign tools, then sign the person or agent marker. To sign tools, make the ASL letter V sign with your dominant index and middle fingers, and hold your non-dominant index finger steady while the rest of your hand is in a fist. Pivot your 'V' fingers around the index finger a few times.
Finish off by signing the person or agent marker, holding both flat, open hands in front of your body with palms facing each other, then sliding both parallel hands downward.
Teach your toddler the plumber sign when you hire a handyman to fix your kitchen or bathroom plumbing.
This is a useful flash card taught best in conjunction with other flash cards describing the task or job at hand.