This is a Glock Sight, model 39930. GLOCK night sights are equipped with contrasting tritium inserts" enabling simple" accurate and quick target alignment in all light conditions. Front fits all models Rear size 6.1mm slim width Fits G42/G43 DISCLAIMER: GLOCK is a federally registered trademark of GLOCK, Inc. and is one of many trademarks owned by GLOCK, Inc. or GLOCK Ges.mbH. Neither Sportsmans Outdoor Superstore nor this site are affiliated in any manner with, or otherwise endorsed by, GLOCK, Inc. or GLOCK Ges.mbH. The use of GLOCK on this page is merely to advertise the sale of GLOCK pistols, parts, or components. For genuine GLOCK, Inc. and GLOCK Ges.mbH products and parts visit www.glock.com.