NIUXX Stacking Kit with Sliding Shelf, Fits for 47-58 cm Washing Machine and Dryer, Ratchet Rope Installation Frame Accessories for Connecting Tumble Washer Dryer, Ideal Housewarming Gift : Amazon.co.uk: Large Appliances
GE Steel Laundry Stacking Kit (White) in the Washer Parts department at Lowes.com
Camtec - Stacking kits and how to organise your washer and dryer