GAIAM Studio Select Ultimate Core Toning Kit FabFitFun. Brand new never used. Get a full-body Pilates workout right from your own home with the Ultimate Core Toning Kit. This kit includes an 8" Mini Ab Ball and a durable 4-looped Core Reformer that mimics the actions of a Pilates reformer using lightweight resistance bands. Intensify your Pilates workout for faster results with these helpful tools.