This TM-27 (TM27) is used to control Gladermatic Roller Door Operators. The coding is set by the combination of 9 dip switches inside the remote each with three positions (+, 0 and -), which is called Trinary coding.
It is compatible with Glidermatic De Luxe GTX-M27 as well as model GTX-M27G, both have the same manufacturer, the same working frequency and the same Trinary coding system.
Sun visor pack available TM27SV .
This garage door remote may look similar to the remote GTXU1 or GTXU2, which indeed are completely different inside and therefore not compatible with each other. TM-27 has marking on the back cover of the transmitter. GTXU1, GTXU2 use 6-volts batteries.