TweetAnybody ever seen the BD Safety Lok syringes? They're different. I guess the purpose of the outer sleeve that locks is so you can't pull the plunger out??? The only other thing that I could think of is after you inject, you slide the outer sleeve up to lock it so the needle can't be accessed. I don't know??? They are some heavy duty jokers.
Tweetya the safety lock is to make the neddle safe after its used, they are also more expensive than the luer lock and you can change the neddle size.