Bowling ball to skid longer before reacting (hooking). Reactive cover stocks finishes include "matte" (aggressive reaction), "shiny" (longer skid distance than matte finish), "pearl" (greatest skid distance among reactive cover stocks), and "hybrid" (combination of skid distance and back end reaction). Duckpin balls weigh each, with up to three balls delivered per round (or "frame") of bowling for one bowler. The duckpin ball has a maximum diameter of , slightly larger than a candlepin ball but, like a candlepin ball, contains no finger holes. Duckpins are correspondingly shorter and lighter than their ten-pin equivalents and it is more difficult to knock them
Bowling ball diameter in the range of to . The surface of the ball is required to include markings to indicate the manufacturer's brand name, the name of the ball, the center of gravity (before drilling), the orientation of the core (the Pin), and the axes of the high and/or low radius of gyration (as applicable). Additionally, markings must include an individual serial number and the logo of the USBC. Holes are allowed to be drilled into a bowling ball for a variety of reasons, and bowlers must be able to demonstrate that such holes can be used as claimed. Up to