These are the replacement O-rings for the Pink Rhino brand laser trainers. Each order comes with two sets of O-rings (4 O-rings total).
If your laser trainer has 3 O-rings on it, these probably won't work. I can't confirm if they are the same size.
Each caliber has different O-Rings required. Be sure to select the correct caliber.
The free shipping rate is for USPS first class mail.
To increase the life of your O-Rings, be sure to lubricate them before each use. You can use any good gun oil.