Here is a nice upgrade/maintenance kit for the Diana Chaser/Airbug/Bandit/Trailscout & Stormrider.  First you get probe seals, as you cycle the bolt probe passes through this and wear eventually causes air to escape.  Also included are additional outer barrel seals and a full set of barrel set screws "2 short/1 long" which are easily misplaced.  Finally you get an upgraded breech screw to replace the cursed hex screw located under the loading tray which is easily stripped.  Kit will include 2 inner barrel probe seals,  4 outer barrel seals, 3 barrel set screws and 1 upgraded breech screw.  Be sure to select .177 or .22 caliber.  GOOD LUCK!