Vista Professional Outdoor Lighting ITT-600-B Black In-Grade Tri-Tap Transformer 600W. Vista's In-grade Tri-Tap (ITT) Series of transformers are ideal for direct burial applications, with it's fully grounded and encapsulated core and coil. The ITT's Ryton™ R4 composite housing along with a black silicone rubber gasket protect against detrimental dust intrusion as well as penetration of water. An industry-first tempered glass inspection window allows for convenient circuit breaker inspection.