A set of chocks for your 1/350th Essex-class carrier or similarly sized warship. These are suited for 1/350th-scale models, and will probably work well on other large carriers and battleships.
Each chock is 5.83mm long, 2.4mm wide and 4.6 mm tall
Scrub the parts in warm, soapy water to remove any mold or printing residue and allow to dry. Paint using acrylic modeling paint (I've used enamels on printed parts before, but some say that the paint won't hold. I recommmend using whatever works for you AFTER test painting a scrap piece of printed material, like the sprue the chocks come on). Then, simply clip the chocks from their mounting sprues with a nice pair of sprue nippers or an X-Acto knife (using appropriate cautionand care, of course) and attach to your model using regular old modeling superglue.