This imaginatively-labeled device is an overdrive pedal by Danelectro, a company reputed not only for its guitars, but also for their inexpensive stomp boxes.
Basically, it's a heavy ivory-coloured steel casing in 1950s retro design. There's a large on/off button with a control LED on top as well as five knobs; at the back, there are in and out phone jacks and a DC in connector; and there's a battery compartment built into its rubbery belly side, with enough space for the hooked-up battery and a spare (very useful). It's quite large and heavy for a stomp box, and that together with aforementioned rubber coating makes for zero slippage if you really use it on the floor. I for one don't, as I use this overdrive effect between my Viscount D9e Hammond organ emulator and my Allsound LC 80 / TH 85 rotary speaker cabinet (aka Leslie).
The leftmost knob controls output volume, the rightmost one the drive level. From slight, tube-amp-ish crunch up to cutting, noisy distortion, there's everything you want; and the three controls in the middle (low/mid/high) are an effective three-band equaliser to shape the sound. Three-band EQs seldomly happen on an overdrive effect; this is the thing that makes the Daddy O. so versatile.
The price is great, too. In the US, the thingy retails for about $60. I initially cursed myself when I had bought mine, but I'm slowly coming to love it. From hard Deep Purple distortion to soft Uriah Heep drive, this is exactly what my organ sound needed. OK, maybe a H&K Tube Factor would do better. But it would cost about six times as much.