Durable, anodized aluminum pen is linked to matching aluminum cube base with 23" nylon-coated aircraft cable for added strength and security. Unique locking design discourages dismantling attempts, yet allows easy refills. Ideal pen for banks, retailers, office and hotel lobbies, tuition offices, unemployment offices, and temp agencies. The Sentry pen's cable cannot be severed with ordinary tools. Sturdy, adhesive-backed aluminum base mounts easily to any clean, hard surface. Base pen uses MMF Industries Jumbo Jogger refills.