Stinger USA Weighted Baseball - Batters Training Aid - Hitting Equipment - Fast Pitch - Softball - Training Ball Now shipped direct from STINGER starting 2/21/16! Technologically Advanced Sand Weighted Baseball is the hottest training aid on the market today. 425 Grams - Regulation Baseball Diameter. Adjustable pressure valve. No glove required-Front or side soft toss to hitter. This amazing device will give you STRENGTH and POWER in the hands, wrists, forearms and shoulders - A MUST HAVE for anyone that is serious about baseball. Pitchers and throwing programs love this ball Perfect for Pre-game batting practice or warm-ups in small areas or confined space. Sand limits the flight of the ball - A REVOLUTIONARY Concept. RESULTS! RESULTS! RESULTS! It makes a good hitter a GREAT Hitter! These balls are the hidden secret of many coaches. Safe for use with any bat. Boxing has a heavy bag for power and strength. This is baseball's equivalent- Hit Harder-Trains hitters to drive the barrel of the bat through the ball