I talked to Brownells today and the tech said they (KDF) offer no caps in their line, but its a option when you order the brake. I will try and contact them. I am not wanting to spend an arm and leg. Shooting and hunting with the brakes is ok, my hearing is gone now so I use the Walker electronic muffs. The lead sled appealed to me as working on loads for a 16" 44 mag Marlin and this little toy will beat you up on the bench.
Jim