User's Manual ; RING VOLUME. Adjusts the ringer volume ; to Low or High setting. DATA PORT ; HOLD KEY HANDSET VOLUME KEY. Changes handset volume by ; pressing Teledex BTX Series User Manual • Original mode • Teledex btx4550 diagram, For customer service call, 4035 (north america) • Teledex Phones.Teledex BTX4550 manual ; Base unit • Coiled handset cord • User guide · Handset • Clear plastic overlay • Line cord ; Contact your supplier or Teledex for Manual for Teledex BTX4550 Phone. View and download the pdf, find answers to frequently asked questions and read feedback from users. ℹ️ Download Teledex BTX4550 Manual (Total Pages: 3) for free in PDF. Find more compatible user manuals for your Teledex BTX4550 Telephone device. Download Teledex Telephone BTX4550 User's Manual · 1) Lift the handset. · 2) Press the STORE key and release it. · 3) Enter the telephone number including PAUSE or Teledex Teledex-Telephone-Btx4550-Users-Manual-464362 BTX4550 to the manual 31008fb4-3aa9-487b-b2f5-74eff697d755. 2015-02-03. : Teledex