We have a number of AT-150 commercial traps with the blue spring. We have some tight terrain and found that it was difficult to turn down the blue spring enough to have a short, soft target. The white springs give us this flexibility. Plus this upgrades the 3/8" stud to 1/2" with double nuts providing more protection to the threaded stud.
Reviewed by: (Verified Buyer) Bill Cope from Cacoosing Gun Club.