Sheldon Signature General-Purpose Incubators Accessories. Combining top-notch and uncompromising quality with an affordable price the Shelf for Sheldon Signature General-Purpose Incubators 1535 23in x 23in Sheldon 5130518 can fulfill your laboratory needs while still offering a great value for the money. Specifications for Shelf for Sheldon Signature General-Purpose Incubators 1535 23in x 23in Sheldon 5130518: Unit: Each Sheldon Signature General-Purpose Incubators 5130518 Accessories