Although the innovative first-generation SLK was considered somewhat effeminate, the current SLK looks like a three quarter scale SL, which is a compliment. The SLK pioneered the retractable hardtop sports car, which adds an extra measure of quietness and security. Available engines include a 228-bhp 3.0L V-6, 300-bhp 3.5L V-6, or the 355-bhp supercharged 5.5L V-8 in the SLK55 AMG. Transmission choices are a 6-speed manual or 7-speed automatic. A vast option list allows customers to personalize their SLK; especially the "designo" packages, which combine interior and exterior trim with a color-coordinated theme.