Stens 385-435 String Trimmer Bump Feed Head Universal String trimmer bump feed head Uses .080-inches, .095-inches or .105-inches diameter line Spool holds 20-foot of .095-inches diameter line Arbor sizes included:; 3/8-inches-24 RHF; ideal for consumer and commercial use Recommended for trimmers under 25cc; Single spool allows for single or dual line indexing