Echo® Speed-Feed® 500 99944200950B Trimmer Head 24 per Case. The Speed-Feed® 500 is the fastest-loading professional bump-to-advance style head in the market. It can be reloaded without disassembly in 30 seconds or less. It features a 40' holding capacity and is pre-loaded with a .095'' Black Diamond® trimmer line. The Bump-to-Advance has been improved on the Speed-Feed® 500 making it easier for the end-user to remain productive throughout the trimming task.