This is a digital delay primarily used to sync digital audio sources with video. Most HD video displays will be behind the audio. This unit will let you tweak the delay rate to sync the two sources. Supports 33khz=7.62ms, 48khz=5.27ms, 96khz=2.73ms, 44.1khz=5.8ms, 88.2khz=2.93ms, 192khz=1.36ms. Has 2 different source inputs each with a choice of coax(RCA)or optical for each. This unit includes remote, box and instructions, Condition is good except for minor scratch on front which is hidden by black marker. In normal light in my AV cabinet the unit looks flawless. This unit works great and has no noticable degrade in audo quality. Price includes shippping and PAYPAL fees.