*This be gone*
I've bought too much stuff recently so I'm selling my Seymour Duncan Double Back Compressor. The 'doubleback' feature allows you to blend in some of the clean, uncompressed signal to retain tone while adding sustain. The doubleback section has a filter to allow you to blend in high frequencies, mids or full range, I usually just have it on full range although high can be good for slap stuff to add super bright punchiness. Other knobs are attack, sustain and volume. Its true bypass and sturdily built although I've just noticed its missing a couple of screws from the back, guess its always been like that and it's still solid.
These retail at £130+, I got it ex-demo in October for £89.50 (I'll enclose the receipt for the rest of the warranty) and it's lived in a pedal bag since then so in good condition but has some light scratches, no original box or manual.
£85 posted.
Can get photos if required.