Get Longer, Straighter And More Consistent Drives. Bonus Yards is a portable golf training aid that helps golfers improve their swing. Attach the device to your driver, and Bonus Yards will help you achieve the proper club angle for longer, straighter drives. May also be used to help read the slope of the greens. Made of durable materials. Compact and lightweight make it easy to bring on any golf outing. Requires no batteries or other power source. Weight: 0.30 lbs.