RAMY

Sounds like a manufacturer specific model number or type. The basic types are single tube, double tube (two singles joined together), triple tube (three tubes joined together), and spirals. The basic difference is going to be lumen output. Lumen is a measure of light, like foot-candles. Basicly, the longer the plasma (arc length) the more efficient the bulb is going to be.

you have not given a complete lamp designation, what ever you given is a part of a LIS ZVEI designation. Any way designation is as follows

TC- Tubular Compact, D- Double type, T- Triple type, EL- Electronics ballast, Without EL is conventional ballast. Based on the type D or T, lamp base and physical dimension will be different but there will be no changes in initial lumen, avg. life and color rendering. Please check it from LIS ZVEI catalog for your self satisfaction.

Thanks