Spring with hook. Models: FS 56 (4144) FS 70 C-E FS 91 FS 111 FS 120 2-MIX FS 131 FS 240 FS 240 C-E FS 260 FS 260 C-E FS 261 FS 261 C-E FS 311 FS 360 C-E - 4147 FS 410 C-E FS 410 C-E L FS 360 C-EM - 4147 FS 410 C-EM FS 361 C-EM FS 411 C-EM FS 460 FS 460 C-EM FS 460 C-EM L FS 461 C-EM FS 490 C-EM FS 491 C-EM FS 510 C-EM FS 560 C-EM FS 561 C-EM KM 56 RC-E MM 56