Spine cassettes are compatible with GBC ProClick Pronto P3000. Easy to edit. Zip open and closed so you can swap pages in and out quickly anywhere, anytime. Spine cassettes help deliver great professional-looking presentations. Using spine cassettes gives documents a unique, contemporary look. Pages lie flat and are held securely in place. Each cassette holds 20 spines. ProClick editing zip tool is sold separately. Spine cassettes are made with a high percentage of recycled material.