Keuffel & Esser 4097x & 4098 5″ Mannheim “EverThere” Slide rule 4097B – Merchant’s4097B 5″ Mannheim “EverThere” Slide rule – 0333934097B 5″ Mannheim “EverThere” Slide rule – 642324097C – “4053-3 like”4097C 5″ Mannheim “EverThere” Slide rule – 0099624097C 5″ Mannheim “EverThere” Slide rule – 277064097D – Expanded Scales4097D 5″ Mannheim “EverThere” Slide rule – 0194324097D 5″ Mannheim “EverThere” Slide rule – 1051304097D 5″ Mannheim “EverThere” Slide rule – 1463204098 – “4053-3 like”4098 5″ Mannheim “EverThere” Slide rule – 184254098 5″ Mannheim “EverThere” Slide rule – 32162