I LOVE these lampsI personally like these
Lamp No DT55/50/RS
Bar Code 49311
Watts 55
MOL in/mm 21.5/546
Avg Life 14000
Bulb T-5
Base 2G11
CT deg K 5000
CRI 82
Approx Initial Lumens 4800
Approx Mean Lumens 4320
55 watts- 21.5 inches long
I use the Fulham Workhorse 220w ballasts with them but don't wire more than 3 55w lamps to it.... it voids the 5yr warranty. Fulham shipped me out a replacement for my 110w setup that burned out. They have less than a 1% failure rate.
Bonsai mums are awesome under these lamps.
Stay Safe!