For pheasants from 6 weeks on (not to be used for breeding cocks). To be used primarily on birds that will be released at 12 to 14 weeks of age. Advantages over metal includes: They are easily applied and removed without a tool. Can be reused. Do not cut into beak as metal bits do. Easy to change sizes as birds mature. Warning: When using C size, for a few days prior to applying the bits, give the birds pelleted food in deep containers. MASH SHOULD NOT BE FED! Can also be used on chickens. Bag of 50.