
Good product. The one with one, two or three keystone slots fits almost every keystone. If you hit one of them when you have four of them, you might not be able to fit all the keystones and line them up next to each other. However, stacking three seems to work with every keystone size I've used in the past.

Realistic Wood Grain Self-Adhesive Furniture Film - 15.7 In X 196 In, White, Easy To Install And Clean, Thick And Full-Coverage For Enhanced Durability
25 Review

Childproof Your Home With ENERLITES Elite Series Screwless Wall Plates - Dark Bronze (10 Pack)
37 Review

ENERLITES Elite Series Screwless Decorator Wall Plate Child Safe Outlet Cover, Gloss Finish, Size 3-Gang 4.68" H X 6.53" L, Unbreakable Polycarbonate Thermoplastic, SI8833-SV, Silver
31 Review

ENERLITES Elite Series Screwless Decorator Wall Plate Child Safe Outlet Cover, Gloss Finish, Size 1-Gang 4.68" H X 2.93" L, Unbreakable Polycarbonate Thermoplastic, SI8831-SV, Silver
20 Review

Wireless Electronic Ballast Interface Certified
8 Review

Robertson Worldwide ISL432T8HEMV AH 3P20160 120-277V 50-60Hz High Power Factor 4 F32T8 Linear Lamp Fluorescent eBallast
6 Review

π‘ Electronic FL Ballast ICN-4P32-N (Formerly ICN-4P32-SC) for 3-4 F32T8 F40T8 F17T8 Lamps, 120V/277V Compatibility
5 Review

Fulham WorkHorse WH2-120-C Adaptable Ballast - 2 Pack
3 Review