Here we have a sliding shelf by Middle Atlantic. The Shelf is brand new and still in the unopened box. I have two of them and the other one is unpacked, pictured on top of the unopened box.
S+H is $20.00 US. Item is sold to the lower 48 states only. NO INTERNATIONAL BIDERS PLEASE. Here are the specs from the Middle Atlantic web site: Filling just a single rack space, our low profile SSL sliding shelf extends 11" on 3/4" nylon roller slides equipped with positive-stop lockouts.
A telescopic rear support mounts to any rack.
The shelf itself is made with an attractive black laminate material. 35 lb. weight capacity.