Redding the BIG Boss, and BIG boss II Reloading prime catcher upgrade. Now catching the spent primers with this device will mean lot less mess dealing with the old primers and trays! You will probably love it so much you will throw away your old original primer tray! The collection tube has been designed to use a standard half inch I.D. tubing.(not included,but can be got at any hardware store) Very simple clip on design, Easy to clip on or off. (designed by me :)) Primer slot director included. This part is 3d Printed by me, I can make as many as you like. See color options above. Made to fit the BIG BOSS Will not fit the BOSS model 72100. The BOSS 72100 is in my store. NOTE: THIS IS FOR THE PLASTIC CATCHER NOT THE PRESS Bulk quantity pricing is available , just email me. See my store for other press models options. Note: Made with 3d printer so may have some small imperfections, but overall looks and works great I