This is a classic stereo delay modeller that provides a wide range of emulations; digital, analog, tape, ping-pong, multi-tap, etc. Select your basic model, tweak to your particular needs then hold down one of the three left-hand switches to store it as a preset on that switch. The last switch is tap tempo. The DL4 can also be used as a 14-second looper, but its real use is as 3 delays in one. Bear in mind this cannot share a PSU; like most Line 6 pedals it needs its own (this does make them more resistant to accidental destruction). Construction-wise, the "switches" are actually buttons that press small cheap switches on the circuit board and some people modify them to use proper switches. One nice feature of this range is the fact that it uses a relay that ensures true bypass and also that if the power dies signal reverts to straight-through. It's not cheap and it's getting a bit long in the tooth - 14 seconds isn't much of a loop these days - so only 4 stars.