This pack includes:

1x Rubber bucking.

1x Silicon bucking.

1x fishbone device.

Shark Hop-up Bucking was originally designed to prevent double feeding.
By having 3 special "fins" inside the bucking, Shark Hop-up Bucking can hold one and only one B.B. tightly in the chamber.

Rubber works best in normal temperatures and the silicon works best in cold weather.

Fishbone device:

Traditional hop-up pressure device can apply uneven pressure on to BB's.

The Fishbone device will apply even pressure onto BB's and provides consistent accuracy.