Micro A/B (LED Version) http://www.loop-master.com/product_info.php?cPath=25&products_id=254 DIMENSIONS: 1.99" X 1.99" X 1.06" USES: Split between your amps: Connect your guitar to "Input" on the Loop-Master, connect amp A to "A" on the Loop-Master and connect amp B to "B" on the Loop-Master. Use for silent tuning: Connect your guitar to the "Input" on the Loop-Master, connect your amp to "A" on the Loop-Master and connect your tuner to "B" on the Loop-Master. You can make any tuner true bypass capable this way. Split between two instruments without unplugging: Connect one guitar to "A" on the Loop-Master and one to "B" on the Loop-Master and connect your amp to "In" on the Loop-Master. Absolutely no bleedover Handmade with the finest components possible for superior tone such as point-to-point military spec silver plated wiring, silver soldering, Switchcraft jacks and a heavy-duty aluminum enclosure. No buffers and no tone-sucking BS. Models with LED's use Boss/Ibanez style 9v 2.1 mm barrel-style adapter for LED power only. Will work without power minus LED indication. Our LED circuits does not screw with your tone. This model includes (1) LED that is a dual-color red/green LED. Click once for red, click again for green.