MAKE SURE YOUR RIFLE IS FULLY UNLOADED & SAFE BEFORE INSTALLING THIS PRODUCT. Easy-Install Globe Sight made compatible w/ M1903-A3 Later Stamped Version of the M1903 Rifle. Slides right over the original front sight block, no modification needed. 2 screws on the bottom secure the hood to the sight base. 2 adjustment hold screws just above the bottom mounting screws help maintain the center alignment of the hood on the block secure those in once you line up the front hash mark on the front of the protector on the muzzle end, with your front sight post. The rear top screw is the last screw, this screw secures your bubble level mount to the base & there is another screw just incase the bubble level does not want to be used. 13 different threaded interchangeable & adjustable apertures, high & low bubble mount kit, complete hardware & tool. Protects the very fragile & often damaged front sight post from impacts. Aids in target acquisition & shot reference down range. Works BEST with 1903-A3 model as it has a circle style rear peep that lines up with the circular shape of the hood & apertures. Take your time ! Aim True. Designed & Made in the USA 3D Printed in PETG+ Black Small business product is made by order . Please allow a few days for processing thank you !! STL Available for purchase ! https://cults3d.com/en/3d-model/tool/m1903-a3-globe-sight-system SELLER TAKES NO RESPONSIBILITY FOR MISUSE OF PRODUCT USE AT YOUR OWN RISK. Warning This product can expose you to chemicals including [name of one or more chemicals], which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm . For more information go to www.P65Warnings.ca.gov/.