The SL training sails can be used on the Optimist or Pram. The luff has been shortened to raise the boom height. Battens have been eliminated for easy storage. This is meant to lessen head injuries and allow for 2 sailors in the boat. Additionally, it has captive webbing at the top of the mast. The clew is not captive which allows the current outhaul system to be used. Comes in 2 colors.