ACT Streetlite Flywheel w/CW01 Counterweight - 86-88 Mazda RX-7 Turbo - 600145-01 86mm they are a 19 Hex

they are a 19 Hex thin-wall lug nut that fits in small bolt holes of most modern aftermarket wheels

93-98 Nissan Skyline (R33) 2

00-05 Toyota MR2 Spyder 1

04-08 Nissan Maxima 3

FM7-HDSS kit features ACT's most popular Heavy Duty pressure plate and most popular street disc

ACT Streetlite Flywheel w/CW01 Counterweight - 86-88 Mazda RX-7 Turbo - 600145-01 86mm they are a 19 Hex600145 01 is a flywheel kit for various Mazda RX 7 and RX 8 applications and comes complete with an ACT counterweight. The flywheel counterweight is required when installing the XACT flywheel on various Mazda RX 7 and RX 8 rotary applications. ACT XACT Streetlite flywheels are considerably lighter than stock and are the most durable flywheel offering from ACT. Materials are properly distributed for maximum strength, lower inertia, good heat tolerance