The StrechCordz Breaststroke Machine strengthens muscles and increases power through outward and inward sweep exercises.áAttaches to a diving board, fence, rail or any stationary object. The StrechCordz Breaststroke Machine includes two paddles each with two tubes and two combo mounting loops. Inside tubes are 27in/68.6cm, outside tubes are 41in/1m. Sold as a complete kit only. No removable components or replacement parts. Available in five resistance levels. The Red resistance has 12 - 31 lbs of resistance.