I noticed while inspecting my LB7DP Uncle Henry that it uses a round lock spring while the other knives use a flat spring. I have one 7OT like this and also had a 7OT that looked like it had two pieces to the spring. I tried posting before on this subject but seems like everyone disappeared or just got tired of me. Just thought someone may have info on some of the differences in locking springs and which type have advantages or disadvantages in strength.