Do you mean these?
Unfortunately, there is no indication in the catalog of how much change there is in suspension height that these perches provide. My guess would be zero from the looks of them.
Your best, assumptionless answer is would be directly from SpiderTrax.
(800) 286-0898
(303) 772-0033
BTW everyone, SpiderTRax's Website has been updated (at least it's new to me).