An alternative technology developed in the US was based on the use of glass modules to be inserted into the main armour; although this arrangement offered a better shaped charge protection, its multiple hit capability was poor. A similar system using glass inserts in the main steel armour was from the late fifties researched for the Soviet "Obiekt 430" prototype of the T-64; this was later developed into the "Combination K" type, having a ceramic compound mixed with the silicon oxide inserts, which offered about 50% better protection against both shaped charge and KE-penetrator threats, compared with a steel armour of the same weight. It was, later in several improved forms, incorporated into the glacis of many subsequent Soviet main battle tank designs. After an initial period of speculation in the West as to its true nature, the characteristics of this type were disclosed when the dissolution of the Soviet Union in 1991 and the introduction of a market system forced the Russian industries to find new customers by highlighting its good qualities; it is today rarely referred to as Chobham armour. Special armour much more similar to Chobham appeared in 1983 under the name of BDD on the T-62M upgrade to the T-62, was first integrated to an armour array in 1986 on the T-72B, and has been a feature of every Soviet/Russian MBT since. In its original iteration, it is built directly into the cast steel turret of the T-72 and required lifting it to perform repairs.