The Bosch D1255RB is an upgraded version of the D1256RB, offering several improvements in terms of functionality and security features. One significant difference is the enhanced encryption capabilities of the D1255RB, providing improved protection against unauthorized access and tampering. Additionally, the D1255RB supports more advanced communication protocols, allowing for smoother integration with modern security systems. Overall, if you’re looking to enhance the security of your premises and take advantage of the latest technology, upgrading to the D1255RB would be a worthwhile investment.