HUB Security SPAC Presentation Deck

Overview of Mount Rainier Acquisition Corp. Strong team with deep networking, sourcing, valuation, diligence and execution capabilities: ✓ Significant technology expertise ✓ Extensive investment and operational experience ✓ Leading family office sponsor with Dominion Capital Matthew Kearney (Chairman & CEO) ■ CEO of high growth technology supported businesses: LeadingResponse (ICV); Screenvision-a arlton/Thomson Joint Venture, growing revenue 300% Chairman of Talent Partners, a Carlyle Group portfolio company Holds or has held board positions on: ■ Rock Holdings Inc (NYSE:RKT); and ■ Telenor ASA (NORWAY:TEL) BOD and Audit chair of (de-spac) Priority Technology Holdings Young Cho (CFO) ■ Experienced CFO and CIO of high growth technology businesses: ■ Hedera Hashgraph; ■ Celsius; and ABRA Previous Executive Director of Illiquid Credit Trading at UBS ■ Previous Director of Special Situations at Citi Bank Christina Favilla (Director) ■ Operations Executive at high growth Fintech company, Ocrolus ■ COO of GE Capital North America from 2012-2017 ■ Board Member of Priority Technology Holdings ■ Director Nominee for Opportunity Financial (De-Spac of FG New America Acquisition Corp) ■ Chair of the Nominating & Governance Committee of Citizens State Bank of Ouray Colorado ■ Former President of Discover Bank Otto Risbakk (Director) CFO of Digi Telecommunications (as of August 1, 2021) CFO of Telenor Denmark, a subsidiary of a $30 Billion EV multinational telco ■ ■ ■ Head of M&A at Telenor from 2012-2019, leading more than 70+ transactions ■ Director of M&A and VP of International Business Development, Oil & Gas at Norsk Hyrdo ■ Former CFO of Norsk Hydro Automotive, Rieter Automotive, and Schlumberger SCREEN VISION MEDIA SV citi CARLTON Jeffery Bistrong (Director) ■ Partner and member of the investment committee of middle market private equity firm HKW-Technology Focused ■ Managing Director of Harris Williams Investment Banking from 2002-2019 ■ Founder of Harris Williams TMT group, leading over 100+ Technology Transactions ■ Director of government software and services company Civix and healthcare software company Kumanu Past board member of HKSE-listed Mobile Telecom Ltd. and nonprofit Northeast Health Systems S STERLING NATIONAL BANK DOMINION CAPITAL ABRA GE RIETER H digi H Schlumberger HUB DMGT Al UBS CITIZENS ESTO STATE BANK DISCOVER Hydro CHW Page 3

View entire presentation