Bought these from Amp-head.com and haven't used them. I bought them to use with a guitar amp that I have sold and no longer need the bias probe. Paid $115+ for both but will sell for $60 plus shipping. US shipping only. http://www.amp-head.com/product_info.php?cPath=21&products_id=70 http://www.amp-head.com/product_info.php?cPath=22&products_id=96 $60 plus shipping...Paypal or USPS money order.