Listen up! What the other guys said!
This is a great product. I got a pristine IC-745 on eBay and read about and started sweating BBs about how it might lose its mind if the RAM board battery crapped out. I mean I thought my rig was destined for Icom Repair Department Hell; you know, six weeks up in Washington and a phone call where the rep says, "Who is this? No, I'm sorry we don't have any record of.."
So I bought this little unit for the peace of mind. It arrived fast (they sent it via USPS priority the *day* I ordered it) and it was a simple operation to remove the old board and plug this one in. These guys even jumpered it for the IC-745; what princes! So now if the lithium battery goes South, you only lose your memory channels, not the radio's intelligence. Also, the battery is in a holder so you don't have to mess with unsoldering the old battery and soldering in the new one.
...you should buy this unit and *then* skulk around on eBay for an IC-745 or IC-751, the product is *that* good!