Abstract: Disclosed is a lightweight caster assembly and modular shelf system for use on an existing collapsible foldable cart with four wheels.

Abstract: A safety pay telephone using conventional telephone mechanical and electrical components mounted within a telephone housing, typically mounted on a wall, with the earpiece and mouthpiece mounted within the telephone. To operate, the user deposits the proper amount of currency and pushes an on/off switch, dials his number, and then places his ear next to the fixed earpiece. A method of retrofitting a conventional telephone with a retrofit housing member that permits that existing handset to be protected within a retrofit housing member. The safety phone is designed for use in prisons so inmates within a prison cannot hang themselves with a handset cord or break a handset and handset cord off for use as a weapon. The safety telephone is also designed for use in environments wherein the telephone is subject to abuse. The safety telephone design reduces the cost of maintenance by eliminating the need to fix and replace telephone components.