Do you use a weight lifting belt?

[Control]

I use mine like this (for squats)

135 x 15 (no belt)
135 x 15 (no belt)
185 x 12 (no belt)
225 x 8 (no belt)
275 x 6 ( belt)
315 x 4 ( belt)
365 x to failure, could be 12 reps could be 20, just depends on how strong I feel that day ( belt)