Thank you for your question regarding the Delta Shower Arm & Flange and I am happy to assist you today.
The shower arm, model RP31554 has a total length of 5 1/2", whereas model U4993-PK has a total length of 6".
If we can assist you with anything else going forward, please do not hesitate to give us a call at 800-345-3358.
Delta Faucet Company
Date published: 2018-02-14