I get more calls from salon owners who have had information from misguided lamp distributors. The Wolff Velocity is not a 5% or 7% lamp.
http://www.wolffsystem.com/
Lamps/velocity.html
From Wolff Systems website you can easily see the specs on each lamp.
Velocity is 3.95% UVB
Velocity Plus is 4.3% UVB
Velocity Extreme is 4.67% UVB
The Velocity is a decent lamp for beginner tanners, however you can please more skin types with a slightly stronger lamp.