Dosho Design WJP009 Windjector Pro Extremely light and easy to use for strengthening core muscles by using air-resistance Endorsed by leading fitness experts and medical professionals as a safe, simple and enjoyable workout Includes a 60-minute instructional DVD, a 16-page training manual and a color poster with a quick 8 minute core workout Ships in three easy-to-assemble pieces weighing less than 2 lbs. total Manufacturer Lifetime Warranty No-impact cushioning effect eliminates strain on joints and muscles