A great accessory pier shelf for the AP900 Pier. Designed and sold by Greg Mueller as an SBIG ST-4 or Powerbrick holder. See it at the muellersatomics website: http://www.muellersatomics.com/PB1200.htm
I use mine as an accessory shelf to Velcro mount my JMI computer and AP900 hand controller. I bought 2 but it turns out I only need one. I'll sell you this one for $45.00. Includes S&H.