Beginning in early 2013, Tyco Fire Protection Products will transition to a reengineered line of 5.6 K-Factor TY-B and TY-FRB series sprinklers that are slightly different in appearance from existing models, but are equivalent in fit and function. While there are a few minor differences between the new and current sprinklers which are detailed below, Tyco’s reengineered sprinkler may be installed and used as a direct substitute for the current sprinkler it is replacing (see conversion chart). Please review the exceptions outlined below as well as the SIN/Part number conversion chart attached to this letter for specific sprinkler configurations involved. Show Less