Abstract: A magazine add-on comprising a platelet arranged to replace the bottom platelet of the magazine and allow measuring the distance, e.g., via an aperture in the platelet, to the magazine's spring-loaded follower either mechanically by an elastic strap, optically by a rangefinder or by measuring the pressure applied by the spring on the platelet. The add-on further displays a number of bullets left in the magazine in a window, either mechanically by numbers on the back of the strap, or electronically on a display attached to the window and connected to the optical or pressure sensor. The add-on is reusable and may be separated and re-attached to various magazines.

Abstract: A magazine add-on comprising a platelet arranged to replace the bottom platelet of the magazine and allow measuring the distance, e.g., via an aperture in the platelet, to the magazine's spring-loaded follower either mechanically by an elastic strap, optically by a rangefinder or by measuring the pressure applied by the spring on the platelet. The add-on further displays a number of bullets left in the magazine in a window, either mechanically by numbers on the back of the strap, or electronically on a display attached to the window and connected to the optical or pressure sensor. The add-on is reusable and may be separated and re-attached to various magazines.