This is a replica of the Rolladen Schneider LS-3, a 15m racing class high performance glider. It first flew in 1976 and during the end of the 70s and the 80s many competitions were flown. I believe it's because the 15 meter class initially didn't allow the use of water-ballast that the first version of the LS-3 had fixed lead ballast in the wings, making them very heavy to mount. The lead strips were also necessary to balance the ls-3's full span flaperons (flap aileron combination). Later versions like the LS-3a had seperate flaps and ailerons and didn't require the lead balancing.

The LS-3 was superseded by the LS-6 in 1983, and is nowadays regaining popularity in the club class competitions.