Has, alot of folks rave over the Tesla seal and how great they are. I installed one in my G1, and am now averaging 860 to 875 fps, after about 1K rounds through it. But to be honest, I think the Apex seal is just as fine a seal as the Tesla. When I re tuned my Crosman SP, the Apex seal looked to be in perfect shape (this with a good 9 to 10 K rounds through the rifle) and left it on instead of replacing it with a new one. Best part is it's shooting just as consistant as it did before the worn out Tarantulla spring gave up the ghost!!!! The Apex is a great seal IMHO, and I'm sure you'll be very satisfied with its performance, tjk