Useful for hobbyists and gunsmiths alike, these replacement screw kits are appropriate for S&W 3-screw pre-1988 revolvers. The complete kit includes 3 Allen side plate screws, Allen mainspring screw, Allen mainspring strain lock screw, trigger overtravel screw, brass plunger and Allen wrench. The side plate screw kit includes 3 Allen side plate screws and Allen wrench. Neither kit contains the large head front side plate screw.