I stuffed a 1/2 inch by 1/4 inch rare earth magnet in the current knog and it works beautifully! absolutely locks both mouth pieces in place without any chance of it slipping.
http://www.amazon.com/gp/product/B001DCT6YU/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B000E63O08&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=014E0EHW15CX67TD8QRA
Toro Performance
http://www.amazon.com/gp/product/B001DCT6YU/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B000E63O08&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=014E0EHW15CX67TD8QRA
Toro Performance