NO-SAG...is a brand name that has become a generic term over the years for a metal CLIP that allows "Spring Up" of wooden framed chairs & couches plus various specialized uses. It employs a simple CLIP with an elongated "J" shape made with two precise holes to allow the STAPLE's legs to hold the spring wire in place after they are "stretched" into position. Omer's NO SAG nose is made to position these 7/16" wide staple legs properly over the HOLE... pattern that is part of the clip itself. The nose allows easy sighting for accurate staple placement every time and there is NO MAGNET to hold the CLIP in place until the first staple is driven...Omer finds that magnets wear out/fall off and generally cause more trouble than they are worth. M1.740 NO SAG uses 17 gauge staples while the M2 and 700 series NO SAG models are tailored to accept the common Senco N wire and DuoFast 7600 or Haubold 700 staple types respectively. No muss...no fuss...simple clean design for industrial reliability demanded in furniture factories.