1996 Tesa Entry Systems International, L.L.C. HT20i Users Manual 1. INTRODUCTION 1.1. Who is TESA? TESA is a lock manufacturer based in Spain that has been T E S A. HT20i. HOTEL LOCKING SYSTEM. USERS MANUAL. 1996 Tesa Entry Systems International, L.L.C.. HT20i Users Manual. 1. INTRODUCTION. 1.1. Who is TESA?Onity Ht20i Manual - Free download as PDF File (.pdf), Text File (.txt) or read online for free. Onity HT20i Manual.