Many eggs use a hinged construction or a custom-designed hinge that keeps the top and bottom halves together and helps the eggs stay closed once shut.
Descriptions call some eggs "ultra-shiny" or "golden," and reviews frequently note a metallic or attractive finish for those gold-style eggs.
Sizes range from small fillable eggs around 2.3"–3.15" tall up to larger fillable eggs at 6", with a single 14" novelty egg also noted.
Options include bright spring colors (blue, yellow, green, pink, violet) and printed designs, plus separate gold/metallic or ultra-shiny finishes for golden eggs.
Some sets are sold prefilled with small toys (for example, yellow rubber ducks), while many other listings are empty, fillable shells intended for candy, small prizes, or crafts.