Buying the Cows' Tails set saves you more than 10% versus buying individual components. Each package comes with 9' of 8.9mm Edelrid Swift Protect Pro Dry dynamic rope (contains aramid fibers for increased cut resistance), 2 pieces of adhesive lined heat shrink tubing, and your choice of:
A) 1 Edelrid bulletproof bent gate, 1 Edelrid bulletproof locking OR
B) 1 Edelrid straight gate, 1 Edelrid bulletproof bent gate OR
C) 1 Edelrid mission straight gate, 1 Edelrid mission bent gate. 

I use 2 nonlocking biners on my cows' tails; using a locking vs nonlocking carabiner is a personal choice.